modules/programs: require manual definition; don't auto-populate attrset

this greatly decreases nix eval time
sane.gui.phosh: remove
2024-02-28 13:32:52 +00:00 · 2024-02-28 13:32:52 +00:00 · 2024-02-28 12:46:38 +00:00 · 2024-02-28 12:37:50 +00:00 · 2024-02-28 10:36:13 +00:00 · 2024-02-28 01:28:05 +00:00
517 changed files with 28352 additions and 58644 deletions
--- a/.gitignore
+++ b/.gitignore
@@ -1,5 +1,4 @@
-/keep
+.working
 result
 result-*
 /secrets/local.nix
-/working
--- a/README.md
+++ b/README.md
@@ -1,3 +1,7 @@
+![hello](doc/hello.gif)
+
+# .❄️≡We|_c0m3 7o m`/ f14k≡❄️.
+
 ## What's Here

 this is the top-level repo from which i configure/deploy all my NixOS machines:
@@ -6,18 +10,18 @@ this is the top-level repo from which i configure/deploy all my NixOS machines:
 - server
 - mobile phone (Pinephone)

-everything outside of <./hosts/> and <./secrets/> is intended for export, to be importable for use by 3rd parties.
+everything outside of [hosts/](./hosts/) and [secrets/](./secrets/) is intended for export, to be importable for use by 3rd parties.
 the only hard dependency for my exported pkgs/modules should be [nixpkgs][nixpkgs].
-building <./hosts/> will require [sops][sops].
+building [hosts/](./hosts/) will require [sops][sops].

 you might specifically be interested in these files (elaborated further in #key-points-of-interest):
- [`sxmo-utils-latest`](./pkgs/additional/sxmo-utils/default.nix)
+- [`sxmo-utils`](./pkgs/additional/sxmo-utils/default.nix)
  - [example SXMO deployment](./hosts/modules/gui/sxmo/default.nix)
 - [my implementation of impermanence](./modules/persist/default.nix)
 - my way of deploying dotfiles/configuring programs per-user:
-  - <./modules/fs/default.nix>
-  - <./modules/programs.nix>
-  - <./modules/users.nix>
+  - [modules/fs/](./modules/fs/default.nix)
+  - [modules/programs/](./modules/programs/default.nix)
+  - [modules/users.nix](./modules/users.nix)

 [nixpkgs]: https://github.com/NixOS/nixpkgs
 [sops]: https://github.com/Mic92/sops-nix
@@ -94,11 +98,16 @@ i.e. you might find value in using these in your own config:
    - persist things to encrypted storage which is unlocked at login time (pam_mount).
    - "persist" cache directories -- to free up RAM -- but auto-wipe them on mount
      and encrypt them to ephemeral keys so they're unreadable post shutdown/unmount.
- `modules/programs.nix`
+- `modules/programs/`
  - like nixpkgs' `programs` options, but allows both system-wide or per-user deployment.
  - allows `fs` and `persist` config values to be gated behind program deployment:
    - e.g. `/home/<user>/.mozilla/firefox` is persisted only for users who
      `sane.programs.firefox.enableFor.user."<user>" = true;`
+  - allows aggressive sandboxing any program:
+    - `sane.programs.firefox.sandbox.method = "bwrap";  # sandbox with bubblewrap`
+    - `sane.programs.firefox.sandbox.whitelistWayland = true;  # allow it to render a wayland window`
+    - `sane.programs.firefox.sandbox.extraHomePaths = [ "Downloads" ];  # allow it read/write access to ~/Downloads`
+    - integrated with `fs` and `persist` modules so that programs' config files and persisted data stores are linked into the sandbox w/o any extra involvement.
 - `modules/users.nix`
  - convenience layer atop the above modules so that you can just write
    `fs.".config/git"` instead of `fs."/home/colin/.config/git"`
--- a/TODO.md
+++ b/TODO.md
@@ -1,12 +1,14 @@
 ## BUGS
- why i need to manually restart `wireguard-wg-ovpns` on servo periodically
-  - else DNS fails
 - ringer (i.e. dino incoming call) doesn't prevent moby from sleeping
+- `nix` operations from lappy hang when `desko` is unreachable
+  - could at least direct the cache to `http://desko-hn:5001`

 ## REFACTORING:
+- consolidate ~/dev and ~/ref
+  - ~/dev becomes a link to ~/ref/cat/mine
+- fold hosts/common/home/ssh.nix -> hosts/common/users/colin.nix

 ### sops/secrets
- attach secrets to the thing they're used by (sane.programs)
 - rework secrets to leverage `sane.fs`
 - remove sops activation script as it's covered by my systemd sane.fs impl

@@ -19,49 +21,66 @@
 - bump nodejs version in lemmy-ui
 - add updateScripts to all my packages in nixpkgs
 - fix lightdm-mobile-greeter for newer libhandy
- port zecwallet-lite to a from-source build
 - REVIEW/integrate jellyfin dataDir config: <https://github.com/NixOS/nixpkgs/pull/233617>
- remove `libsForQt5.callPackage` broadly: <https://github.com/NixOS/nixpkgs/issues/180841>

 #### upstreaming to non-nixpkgs repos
 - gtk: build schemas even on cross compilation: <https://github.com/NixOS/nixpkgs/pull/247844>
- sxmo: add new app entries


 ## IMPROVEMENTS:
 ### security/resilience
- matrix/ntfy: automatically add the ntfy.uninsane.org push URL as part of synapse launch
- ntfy: use a more secure topic
 - validate duplicity backups!
 - encrypt more ~ dirs (~/archives, ~/records, ..?)
  - best to do this after i know for sure i have good backups
- have `sane.programs` be wrapped such that they run in a cgroup?
-  - at least, only give them access to the portion of the fs they *need*.
-  - Android takes approach of giving each app its own user: could hack that in here.
-  - **systemd-run** takes a command and runs it in a temporary scope (cgroup)
-    - presumably uses the same options as systemd services
-    - see e.g. <https://github.com/NixOS/nixpkgs/issues/113903#issuecomment-857296349>
-  - flatpak does this, somehow
-  - apparmor?  SElinux?  (desktop) "portals"?
-  - see Spectrum OS; Alyssa Ross; etc
-  - bubblewrap-based sandboxing: <https://github.com/nixpak/nixpak>
+- /mnt/desko/home, etc, shouldn't include secrets (~/private)
+  - 95% of its use is for remote media access and stuff which isn't in VCS (~/records)
+- port all sane.programs to be sandboxed
+  - enforce that all `environment.packages` has a sandbox profile (or explicitly opts out)
+  - revisit "non-sandboxable" apps and check that i'm not actually just missing mountpoints
+    - LL_FS_RW=/ isn't enough -- need all mount points like `=/:/proc:/sys:...`.
+  - ensure non-bin package outputs are linked for sandboxed apps
+    - i.e. `outputs.man`, `outputs.debug`, `outputs.doc`, ...
+  - lock down dbus calls within the sandbox
+    - otherwise anyone can `systemd-run --user ...` to potentially escape a sandbox
+    - <https://github.com/flatpak/xdg-dbus-proxy>
+  - remove `.ssh` access from Firefox!
+    - limit access to `~/knowledge/secrets` through an agent that requires GUI approval, so a firefox exploit can't steal all my logins
+  - port sane-sandboxed to a compiled language (hare?)
+    - it adds like 50-70ms launch time _on my laptop_. i'd hate to know how much that is on the pinephone.
+- make dconf stuff less monolithic
+  - i.e. per-app dconf profiles for those which need it. possible static config.
 - canaries for important services
  - e.g. daily email checks; daily backup checks
  - integrate `nix check` into Gitea actions?

 ### user experience
-#### moby
- fix cpuidle (gets better power consumption): <https://xnux.eu/log/077.html>
 - install apps:
  - display QR codes for WiFi endpoints: <https://linuxphoneapps.org/apps/noappid.wisperwind.wifi2qr/>
-  - shopping list: <https://linuxphoneapps.org/apps/ro.hume.cosmin.shoppinglist/>
-  - offline Wikipedia
+  - shopping list (not in nixpkgs): <https://linuxphoneapps.org/apps/ro.hume.cosmin.shoppinglist/>
+  - offline Wikipedia (or, add to `wike`)
+  - offline docs viewer (gtk): <https://github.com/workbenchdev/Biblioteca>
+  - some type of games manager/launcher
+    - Gnome Highscore (retro games)?: <https://gitlab.gnome.org/World/highscore>
+  - better maps for mobile (Osmin (QtQuick)? Pure Maps (Qt/Kirigami)? Gnome Maps is improved in 45)
+  - note-taking app: <https://linuxphoneapps.org/categories/note-taking/>
+  - OSK overlay specifically for mobile gaming
+    - i.e. mock joysticks, for use with SuperTux and SuperTuxKart
+- install mobile-friendly games:
+  - Shattered Pixel Dungeon (nixpkgs `shattered-pixel-dungeon`; doesn't cross-compile b/c openjdk/libIDL) <https://github.com/ebolalex/shattered-pixel-dungeon>
+  - UnCiv (Civ V clone; nixpkgs `unciv`; doesn't cross-compile):  <https://github.com/yairm210/UnCiv>
+  - Simon Tatham's Puzzle Collection (not in nixpkgs) <https://git.tartarus.org/?p=simon/puzzles.git>
+  - Shootin Stars  (Godot; not in nixpkgs) <https://gitlab.com/greenbeast/shootin-stars>
+  - numberlink (generic name for Flow Free). not packaged in Nix
+  - Neverball (https://neverball.org/screenshots.php). nix: as `neverball`
+  - blurble (https://linuxphoneapps.org/games/app.drey.blurble/). nix: not as of 2024-02-05
+
+#### moby
+- fix cpuidle (gets better power consumption): <https://xnux.eu/log/077.html>
 - SwayNC:
  - don't show MPRIS if no players detected
    - this is a problem of playerctld, i guess
  - add option to change audio output
  - fix colors (red alert) to match overall theme
-  - extend width to 100% of portrait mode
 - moby: tune GPS
  - run only geoclue, and not gpsd, to save power?
  - tune QGPS setting in eg25-control, for less jitter?
@@ -70,17 +89,13 @@
  - manually do smoothing, as some layer between mepo and geoclue/gpsd?
 - moby: show battery state on ssh login
 - moby: improve gPodder launch time
- sxmo: port to swaybar like i use on desktop
-  - users in #sxmo claim it's way better perf
- sxmo: fix youtube scripts (package youtube-cli)
 - moby: theme GTK apps (i.e. non-adwaita styles)
-  - combine multiple icon themes to get one which has the full icon set?
-  - get adwaita-icon-theme to ship everything even when cross-compiled?
  - especially, make the menubar collapsible
  - try Gradience tool specifically for theming adwaita? <https://linuxphoneapps.org/apps/com.github.gradienceteam.gradience/>
- phog: remove the gnome-shell runtime dependency to save hella closure size

 #### non-moby
+- RSS: integrate a paywall bypass
+  - e.g. self-hosted [ladder](https://github.com/everywall/ladder) (like 12ft.io)
 - neovim: set up language server (lsp; rnix-lsp; nvim-lspconfig)
 - Helix: make copy-to-system clipboard be the default
 - firefox/librewolf: persist history
@@ -98,16 +113,13 @@
  - could change junk filter from "no DKIM success" to explicit "DKIM failed"

 ### perf
+- debug nixos-rebuild times
+  - i bet sane.programs adds a LOT of time, with how it automatically creates an attrs for EVERY package in nixpkgs.
 - add `pkgs.impure-cached.<foo>` package set to build things with ccache enabled
  - every package here can be auto-generated, and marked with some env var so that it doesn't pollute the pure package set
  - would be super handy for package prototyping!
- get moby to build without binfmt emulation (i.e. make all emulation explicit)
-  - then i can distribute builds across servo + desko, and also allow servo to pull packages from desko w/o worrying about purity
-

 ## NEW FEATURES:
 - migrate MAME cabinet to nix
  - boot it from PXE from servo?
- deploy to new server, and use it as a remote builder
 - enable IPv6
- package lemonade lemmy app: <https://linuxphoneapps.org/apps/ml.mdwalters.lemonade/>
--- a/doc/hello.gif
+++ b/doc/hello.gif
--- a/flake.lock
+++ b/flake.lock
@@ -1,20 +1,20 @@
 {
  "nodes": {
-    "flake-utils": {
+    "flake-parts": {
      "inputs": {
-        "systems": "systems"
+        "nixpkgs-lib": "nixpkgs-lib"
      },
      "locked": {
-        "lastModified": 1687709756,
-        "narHash": "sha256-Y5wKlQSkgEK2weWdOu4J3riRd+kV/VCgHsqLNTTWQ/0=",
-        "owner": "numtide",
-        "repo": "flake-utils",
-        "rev": "dbabf0ca0c0c4bce6ea5eaf65af5cb694d2082c7",
+        "lastModified": 1698882062,
+        "narHash": "sha256-HkhafUayIqxXyHH1X8d9RDl1M2CkFgZLjKD3MzabiEo=",
+        "owner": "hercules-ci",
+        "repo": "flake-parts",
+        "rev": "8c9fa2545007b49a5db5f650ae91f227672c3877",
        "type": "github"
      },
      "original": {
-        "owner": "numtide",
-        "repo": "flake-utils",
+        "owner": "hercules-ci",
+        "repo": "flake-parts",
        "type": "github"
      }
    },
@@ -35,34 +35,104 @@
        "type": "github"
      }
    },
-    "nixpkgs-stable": {
+    "nix-fast-build": {
+      "inputs": {
+        "flake-parts": "flake-parts",
+        "nixpkgs": "nixpkgs",
+        "treefmt-nix": "treefmt-nix"
+      },
      "locked": {
-        "lastModified": 1698544399,
-        "narHash": "sha256-vhRmPyEyoPkrXF2iykBsWHA05MIaOSmMRLMF7Hul6+s=",
+        "lastModified": 1703607026,
+        "narHash": "sha256-Emh0BPoqlS4ntp2UJrwydXfIP4qIMF0VBB2FUE3/M/E=",
+        "owner": "Mic92",
+        "repo": "nix-fast-build",
+        "rev": "4376b8a33b217ee2f78ba3dcff01a3e464d13a46",
+        "type": "github"
+      },
+      "original": {
+        "owner": "Mic92",
+        "repo": "nix-fast-build",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1698890957,
+        "narHash": "sha256-DJ+SppjpPBoJr0Aro9TAcP3sxApCSieY6BYBCoWGUX8=",
        "owner": "NixOS",
        "repo": "nixpkgs",
-        "rev": "d87c5d8c41c9b3b39592563242f3a448b5cc4bc9",
+        "rev": "c082856b850ec60cda9f0a0db2bc7bd8900d708c",
        "type": "github"
      },
      "original": {
        "owner": "NixOS",
-        "ref": "release-23.05",
+        "ref": "nixpkgs-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "nixpkgs-lib": {
+      "locked": {
+        "dir": "lib",
+        "lastModified": 1698611440,
+        "narHash": "sha256-jPjHjrerhYDy3q9+s5EAsuhyhuknNfowY6yt6pjn9pc=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "0cbe9f69c234a7700596e943bfae7ef27a31b735",
+        "type": "github"
+      },
+      "original": {
+        "dir": "lib",
+        "owner": "NixOS",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "nixpkgs-next-unpatched": {
+      "locked": {
+        "lastModified": 1708992120,
+        "narHash": "sha256-t/8QV+lEroW5fK44w5oEUalIM0eYYVGs833AHDCIl4s=",
+        "owner": "nixos",
+        "repo": "nixpkgs",
+        "rev": "6daf4de0662e1d895d220a4a4ddb356eb000abe9",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nixos",
+        "ref": "staging-next",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "nixpkgs-stable": {
+      "locked": {
+        "lastModified": 1708819810,
+        "narHash": "sha256-1KosU+ZFXf31GPeCBNxobZWMgHsSOJcrSFA6F2jhzdE=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "89a2a12e6c8c6a56c72eb3589982c8e2f89c70ea",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "release-23.11",
        "repo": "nixpkgs",
        "type": "github"
      }
    },
    "nixpkgs-unpatched": {
      "locked": {
-        "lastModified": 1698611440,
-        "narHash": "sha256-jPjHjrerhYDy3q9+s5EAsuhyhuknNfowY6yt6pjn9pc=",
+        "lastModified": 1708995544,
+        "narHash": "sha256-YJgLopKOKVTggnKzjX4OiAS22hx/vNv397DcsAyTZgY=",
        "owner": "nixos",
        "repo": "nixpkgs",
-        "rev": "0cbe9f69c234a7700596e943bfae7ef27a31b735",
+        "rev": "5bd8df40204f47a12263f3614c72cd5b6832a9a0",
        "type": "github"
      },
      "original": {
        "owner": "nixos",
-        "ref": "nixos-unstable",
+        "ref": "master",
        "repo": "nixpkgs",
        "type": "github"
      }
@@ -70,6 +140,8 @@
    "root": {
      "inputs": {
        "mobile-nixos": "mobile-nixos",
+        "nix-fast-build": "nix-fast-build",
+        "nixpkgs-next-unpatched": "nixpkgs-next-unpatched",
        "nixpkgs-unpatched": "nixpkgs-unpatched",
        "sops-nix": "sops-nix",
        "uninsane-dot-org": "uninsane-dot-org"
@@ -83,11 +155,11 @@
        "nixpkgs-stable": "nixpkgs-stable"
      },
      "locked": {
-        "lastModified": 1698548647,
-        "narHash": "sha256-7c03OjBGqnwDW0FBaBc+NjfEBxMkza+dxZGJPyIzfFE=",
+        "lastModified": 1708987867,
+        "narHash": "sha256-k2lDaDWNTU5sBVHanYzjDKVDmk29RHIgdbbXu5sdzBA=",
        "owner": "Mic92",
        "repo": "sops-nix",
-        "rev": "632c3161a6cc24142c8e3f5529f5d81042571165",
+        "rev": "a1c8de14f60924fafe13aea66b46157f0150f4cf",
        "type": "github"
      },
      "original": {
@@ -96,34 +168,39 @@
        "type": "github"
      }
    },
-    "systems": {
+    "treefmt-nix": {
+      "inputs": {
+        "nixpkgs": [
+          "nix-fast-build",
+          "nixpkgs"
+        ]
+      },
      "locked": {
-        "lastModified": 1681028828,
-        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
-        "owner": "nix-systems",
-        "repo": "default",
-        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "lastModified": 1698438538,
+        "narHash": "sha256-AWxaKTDL3MtxaVTVU5lYBvSnlspOS0Fjt8GxBgnU0Do=",
+        "owner": "numtide",
+        "repo": "treefmt-nix",
+        "rev": "5deb8dc125a9f83b65ca86cf0c8167c46593e0b1",
        "type": "github"
      },
      "original": {
-        "owner": "nix-systems",
-        "repo": "default",
+        "owner": "numtide",
+        "repo": "treefmt-nix",
        "type": "github"
      }
    },
    "uninsane-dot-org": {
      "inputs": {
-        "flake-utils": "flake-utils",
        "nixpkgs": [
          "nixpkgs-unpatched"
        ]
      },
      "locked": {
-        "lastModified": 1698634059,
-        "narHash": "sha256-+Oyv6vDyCtBzab/5cTG0nUrHD9gj7KgGfD4D1Rn4fCk=",
+        "lastModified": 1707981105,
+        "narHash": "sha256-YCU1eNslBHabjP+OCY+BxPycEFO9SRUts10MrN9QORE=",
        "ref": "refs/heads/master",
-        "rev": "2419750ca98fc04af42c91e50c49a29c68d465d2",
-        "revCount": 210,
+        "rev": "bb10cd8853d05191e4d62947d93687c462e92c30",
+        "revCount": 235,
        "type": "git",
        "url": "https://git.uninsane.org/colin/uninsane"
      },
--- a/flake.nix
+++ b/flake.nix
@@ -29,22 +29,24 @@
    # - daily:
    #   - nixos-unstable cut from master after enough packages have been built in caches.
    # - every 6 hours:
-    #   - master auto-merged into staging.
+    #   - master auto-merged into staging and staging-next
    #   - staging-next auto-merged into staging.
    # - manually, approximately once per month:
    #   - staging-next is cut from staging.
    #   - staging-next merged into master.
    #
    # which branch to source from?
-    # - for everyday development, prefer `nixos-unstable` branch, as it provides good caching.
-    # - if need to test bleeding updates (e.g. if submitting code into staging):
-    #   - use `staging-next` if it's been cut (i.e. if there's an active staging-next -> master PR)
-    #   - use `staging` if no staging-next branch has been cut.
+    # - nixos-unstable: for everyday development; it provides good caching
+    # - master: temporarily if i'm otherwise cherry-picking lots of already-applied patches
+    # - staging-next: if testing stuff that's been PR'd into staging, i.e. base library updates.
+    # - staging: maybe if no staging-next -> master PR has been cut yet?
    #
    # <https://github.com/nixos/nixpkgs/tree/nixos-unstable>
-    nixpkgs-unpatched.url = "github:nixos/nixpkgs?ref=nixos-unstable";
-    # nixpkgs-unpatched.url = "github:nixos/nixpkgs?ref=staging-next";
-    # nixpkgs-unpatched.url = "github:nixos/nixpkgs?ref=staging";
+    # nixpkgs-unpatched.url = "github:nixos/nixpkgs?ref=nixos-unstable";
+    nixpkgs-unpatched.url = "github:nixos/nixpkgs?ref=master";
+    # nixpkgs-unpatched.url = "github:nixos/nixpkgs?ref=nixos-staging";
+    # nixpkgs-unpatched.url = "github:nixos/nixpkgs?ref=nixos-staging-next";
+    nixpkgs-next-unpatched.url = "github:nixos/nixpkgs?ref=staging-next";

    mobile-nixos = {
      # <https://github.com/nixos/mobile-nixos>
@@ -55,6 +57,10 @@
      url = "github:nixos/mobile-nixos?ref=d25d3b87e7f300d8066e31d792337d9cd7ecd23b";
      flake = false;
    };
+    nix-fast-build = {
+      # https://github.com/Mic92/nix-fast-build
+      url = "github:Mic92/nix-fast-build";
+    };
    sops-nix = {
      # <https://github.com/Mic92/sops-nix>
      # used to distribute secrets to my hosts
@@ -73,7 +79,9 @@
  outputs = {
    self,
    nixpkgs-unpatched,
+    nixpkgs-next-unpatched ? nixpkgs-unpatched,
    mobile-nixos,
+    nix-fast-build,
    sops-nix,
    uninsane-dot-org,
    ...
@@ -91,39 +99,52 @@
      # rather than apply our nixpkgs patches as a flake input, do that here instead.
      # this (temporarily?) resolves the bad UX wherein a subflake residing in the same git
      # repo as the main flake causes the main flake to have an unstable hash.
-      nixpkgs = (import ./nixpatches/flake.nix).outputs {
-        self = nixpkgs;
-        nixpkgs = nixpkgs-unpatched;
+      patchNixpkgs = variant: nixpkgs: (import ./nixpatches/flake.nix).outputs {
+        inherit variant nixpkgs;
+        self = patchNixpkgs variant nixpkgs;
      } // {
-        # provide values that nixpkgs ordinarily sources from the flake.lock file,
-        # inaccessible to it here because of the import-from-derivation.
-        # rev and shortRev seem to not always exist (e.g. if the working tree is dirty),
-        # so those are made conditional.
+        # sourceInfo includes fields (square brackets for the ones which are not always present):
+        # - [dirtyRev]
+        # - [dirtyShortRev]
+        # - lastModified
+        # - lastModifiedDate
+        # - narHash
+        # - outPath
+        # - [rev]
+        # - [revCount]
+        # - [shortRev]
+        # - submodules
        #
-        # these values impact the name of a produced nixos system. having date/rev in the
-        # `readlink /run/current-system` store path helps debuggability.
-        inherit (self) lastModifiedDate lastModified;
-      } // optionalAttrs (self ? rev) {
-        inherit (self) rev;
-      } // optionalAttrs (self ? shortRev) {
-        inherit (self) shortRev;
-      };
+        # these values are used within nixpkgs:
+        # - to give a friendly name to the nixos system (`readlink /run/current-system` -> `...nixos-system-desko-24.05.20240227.dirty`)
+        # - to alias `import <nixpkgs>` so that nix uses the system's nixpkgs when called externally (supposedly).
+        #
+        # these values seem to exist both within the `sourceInfo` attrset and at the top-level.
+        # for a list of all implicit flake outputs (which is what these seem to be):
+        # $ nix-repl
+        # > lf .
+        # > <tab>
+        inherit (self) sourceInfo;
+      } // self.sourceInfo;

-      nixpkgsCompiledBy = system: nixpkgs.legacyPackages."${system}";
+      nixpkgs' = patchNixpkgs "master" nixpkgs-unpatched;
+      nixpkgsCompiledBy = system: nixpkgs'.legacyPackages."${system}";

-      evalHost = { name, local, target }: nixpkgs.lib.nixosSystem {
+      evalHost = { name, local, target, light ? false, nixpkgs ? nixpkgs' }: nixpkgs.lib.nixosSystem {
        system = target;
        modules = [
          {
-            nixpkgs = (if (local != null) then {
-              buildPlatform = local;
-            } else {}) // {
-              # TODO: does the earlier `system` arg to nixosSystem make its way here?
-              hostPlatform.system = target;
-            };
-            # nixpkgs.buildPlatform = local;  # set by instantiate.nix instead
+            nixpkgs.buildPlatform.system = local;
            # nixpkgs.config.replaceStdenv = { pkgs }: pkgs.ccacheStdenv;
          }
+          (optionalAttrs (local != target) {
+            # XXX(2023/12/11): cache.nixos.org uses `system = ...` instead of `hostPlatform.system`, and that choice impacts the closure of every package.
+            # so avoid specifying hostPlatform.system on non-cross builds, so i can use upstream caches.
+            nixpkgs.hostPlatform.system = target;
+          })
+          (optionalAttrs light {
+            sane.enableSlowPrograms = false;
+          })
          (import ./hosts/instantiate.nix { hostName = name; })
          self.nixosModules.default
          self.nixosModules.passthru
@@ -136,39 +157,24 @@
        ];
      };
    in {
-      nixosConfigurations =
-        let
+      nixosConfigurations = let
        hosts = {
          servo       = { name = "servo";  local = "x86_64-linux"; target = "x86_64-linux";  };
          desko       = { name = "desko";  local = "x86_64-linux"; target = "x86_64-linux";  };
+          desko-light = { name = "desko";  local = "x86_64-linux"; target = "x86_64-linux";  light = true; };
          lappy       = { name = "lappy";  local = "x86_64-linux"; target = "x86_64-linux";  };
+          lappy-light = { name = "lappy";  local = "x86_64-linux"; target = "x86_64-linux";  light = true; };
          moby        = { name = "moby";   local = "x86_64-linux"; target = "aarch64-linux"; };
+          moby-light  = { name = "moby";   local = "x86_64-linux"; target = "aarch64-linux"; light = true; };
          rescue      = { name = "rescue"; local = "x86_64-linux"; target = "x86_64-linux";  };
        };
-          # cross-compiled builds: instead of emulating the host, build using a cross-compiler.
-          # - these are faster to *build* than the emulated variants (useful when tweaking packages),
-          # - but fewer of their packages can be found in upstream caches.
-          cross = mapAttrValues evalHost hosts;
-          emulated = mapAttrValues
-            ({name, local, target}: evalHost {
-              inherit name target;
-              local = null;
-            })
-            hosts;
-          prefixAttrs = prefix: attrs: mapAttrs'
-            (name: value: {
-              name = prefix + name;
-              inherit value;
-            })
-            attrs;
-        in
-          (prefixAttrs "cross-" cross) //
-          (prefixAttrs "emulated-" emulated) // {
-            # prefer native builds for these machines:
-            inherit (emulated) servo desko lappy rescue;
-            # prefer cross-compiled builds for these machines:
-            inherit (cross) moby;
-          };
+        hostsNext = mapAttrs' (h: v: {
+          name = "${h}-next";
+          value = v // { nixpkgs = patchNixpkgs "staging-next" nixpkgs-next-unpatched; };
+        }) hosts;
+      in mapAttrValues evalHost (
+        hosts // hostsNext
+      );

      # unofficial output
      # this produces a EFI-bootable .img file (GPT with a /boot partition and a system (/ or /nix) partition).
@@ -187,25 +193,30 @@
      imgs = mapAttrValues (host: host.config.system.build.img) self.nixosConfigurations;

      # unofficial output
+      hostConfigs = mapAttrValues (host: host.config) self.nixosConfigurations;
+      hostSystems = mapAttrValues (host: host.config.system.build.toplevel) self.nixosConfigurations;
      hostPkgs = mapAttrValues (host: host.config.system.build.pkgs) self.nixosConfigurations;
      hostPrograms = mapAttrValues (host: mapAttrValues (p: p.package) host.config.sane.programs) self.nixosConfigurations;

+      patched.nixpkgs = nixpkgs';
+
      overlays = {
        # N.B.: `nix flake check` requires every overlay to take `final: prev:` at defn site,
        #   hence the weird redundancy.
        default = final: prev: self.overlays.pkgs final prev;
        sane-all = final: prev: import ./overlays/all.nix final prev;
-        disable-flakey-tests = final: prev: import ./overlays/disable-flakey-tests.nix final prev;
        pkgs = final: prev: import ./overlays/pkgs.nix final prev;
        pins = final: prev: import ./overlays/pins.nix final prev;
        preferences = final: prev: import ./overlays/preferences.nix final prev;
-        optimizations = final: prev: import ./overlays/optimizations.nix final prev;
        passthru = final: prev:
          let
            mobile = (import "${mobile-nixos}/overlay/overlay.nix");
-            uninsane = uninsane-dot-org.overlay;
+            uninsane = uninsane-dot-org.overlays.default;
+            # TODO: why do i have to use `self.inputs.nix-fast-build` instead of just `nix-fast-build` here?
+            nix-fast-build = (_: prev: self.inputs.nix-fast-build.packages."${prev.stdenv.system}" or {});
          in
            (mobile final prev)
+            // (nix-fast-build final prev)
            // (uninsane final prev)
          ;
      };
@@ -234,23 +245,27 @@
      # extract only our own packages from the full set.
      # because of `nix flake check`, we flatten the package set and only surface x86_64-linux packages.
      packages = mapAttrs
-        (system: allPkgs:
-          allPkgs.lib.filterAttrs (name: pkg:
+        (system: passthruPkgs: passthruPkgs.lib.filterAttrs
+          (name: pkg:
            # keep only packages which will pass `nix flake check`, i.e. keep only:
            # - derivations (not package sets)
            # - packages that build for the given platform
            (! elem name [ "feeds" "pythonPackagesExtensions" ])
-            && (allPkgs.lib.meta.availableOn allPkgs.stdenv.hostPlatform pkg)
+            && (passthruPkgs.lib.meta.availableOn passthruPkgs.stdenv.hostPlatform pkg)
          )
          (
            # expose sane packages and chosen inputs (uninsane.org)
-            (import ./pkgs { pkgs = allPkgs; }) // {
-              inherit (allPkgs) uninsane-dot-org;
+            (import ./pkgs { pkgs = passthruPkgs; }) // {
+              inherit (passthruPkgs) uninsane-dot-org;
            }
          )
        )
        # self.legacyPackages;
-        { inherit (self.legacyPackages) x86_64-linux; }
+        {
+          x86_64-linux = (nixpkgsCompiledBy "x86_64-linux").appendOverlays [
+            self.overlays.passthru
+          ];
+        }
      ;

      apps."x86_64-linux" =
@@ -258,17 +273,52 @@
          pkgs = self.legacyPackages."x86_64-linux";
          sanePkgs = import ./pkgs { inherit pkgs; };
          deployScript = host: addr: action: pkgs.writeShellScript "deploy-${host}" ''
-            nix build '.#nixosConfigurations.${host}.config.system.build.toplevel' --out-link ./result-${host} $@
-            sudo nix sign-paths -r -k /run/secrets/nix_serve_privkey $(readlink ./result-${host})
+            host="${host}"
+            addr="${addr}"
+            action="${if action != null then action else ""}"
+            runOnTarget() {
+              # run the command ($@) on the machine we're deploying to.
+              # if that's a remote machine, then do it via ssh, else local shell.
+              if [ -n "$addr" ]; then
+                ssh "$addr" "$@"
+              else
+                "$@"
+              fi
+            }

-            # XXX: this triggers another config eval & (potentially) build.
-            # if the config changed between these invocations, the above signatures might not apply to the deployed config.
-            # let the user handle that edge case by re-running this whole command
-            nixos-rebuild --flake '.#${host}' ${action} --target-host colin@${addr} --use-remote-sudo $@
+            nix build ".#nixosConfigurations.$host.config.system.build.toplevel" --out-link "./result-$host" "$@"
+            storePath="$(readlink ./result-$host)"
+
+            # mimic `nixos-rebuild --target-host`, in effect:
+            # - nix-copy-closure ...
+            # - nix-env --set ...
+            # - switch-to-configuration <boot|dry-activate|switch|test|>
+            # avoid the actual `nixos-rebuild` for a few reasons:
+            # - fewer nix evals
+            # - more introspectability and debuggability
+            # - sandbox friendliness (especially: `git` doesn't have to be run as root)
+
+            if [ -n "$addr" ]; then
+              sudo nix store sign -r -k /run/secrets/nix_serve_privkey "$storePath"
+              # add more `-v` for more verbosity (up to 5).
+              # builders-use-substitutes false: optimizes so that the remote machine doesn't try to get paths from its substituters.
+              #   we already have all paths here, and the remote substitution is slow to check and SERIOUSLY flaky on moby in particular.
+              nix copy -vv --option builders-use-substitutes false --to "ssh-ng://$addr" "$storePath"
+            fi
+
+            if [ -n "$action" ]; then
+              runOnTarget sudo nix-env -p /nix/var/nix/profiles/system --set "$storePath"
+              runOnTarget sudo "$storePath/bin/switch-to-configuration" "$action"
+            fi
          '';
+          deployApp = host: addr: action: {
+            type = "app";
+            program = ''${deployScript host addr action}'';
+          };

          # pkg updating.
          # a cleaner alternative lives here: <https://discourse.nixos.org/t/how-can-i-run-the-updatescript-of-personal-packages/25274/2>
+          # mkUpdater :: [ String ] -> { type = "app"; program = path; }
          mkUpdater = attrPath: {
            type = "app";
            program = let
@@ -293,7 +343,7 @@
              } else {}
            )
            (pkgs.lib.getAttrFromPath basePath sanePkgs);
-          mkUpdaters = { ignore ? [] }@opts: basePath:
+          mkUpdaters = { ignore ? [], flakePrefix ? [] }@opts: basePath:
            let
              updaters = mkUpdatersNoAliases opts basePath;
              invokeUpdater = name: pkg:
@@ -303,7 +353,7 @@

                  # in case `name` has a `.` in it, we have to quote it
                  escapedPath = builtins.map (p: ''"${p}"'') fullPath;
-                  updatePath = builtins.concatStringsSep "." ([ "update" "pkgs" ] ++ escapedPath);
+                  updatePath = builtins.concatStringsSep "." (flakePrefix ++ escapedPath);
                in pkgs.lib.optionalString doUpdateByDefault (
                  pkgs.lib.escapeShellArgs [
                    "nix" "run" ".#${updatePath}"
@@ -311,8 +361,9 @@
                );
            in {
              type = "app";
+              # top-level app just invokes the updater of everything one layer below it
              program = builtins.toString (pkgs.writeShellScript
-                (builtins.concatStringsSep "-" (["update"] ++ basePath))
+                (builtins.concatStringsSep "-" (flakePrefix ++ basePath))
                (builtins.concatStringsSep
                  "\n"
                  (pkgs.lib.mapAttrsToList invokeUpdater updaters)
@@ -332,7 +383,11 @@
                - `nix run '.#update.feeds'`
                  - updates metadata for all feeds
                - `nix run '.#init-feed' <url>`
-                - `nix run '.#deploy-{lappy,moby,moby-test,servo}' [nixos-rebuild args ...]`
+                - `nix run '.#deploy.{desko,lappy,moby,servo}[-light|-test]' [nix args ...]`
+                  - build and deploy the host
+                - `nix run '.#preDeploy.{desko,lappy,moby,servo}[-light]' [nix args ...]`
+                  - copy closures to a host, but don't activate it
+                  - or `nix run '.#preDeploy'` to target all hosts
                - `nix run '.#check'`
                  - make sure all systems build; NUR evaluates

@@ -346,48 +401,107 @@
              nix flake show --option allow-import-from-derivation true
            '');
          };
-          update.pkgs = mkUpdaters { ignore = [ ["feeds"] ]; } [];
-          update.feeds = mkUpdaters {} [ "feeds" ];
+          # wrangle some names to get package updaters which refer back into the flake, but also conditionally ignore certain paths (e.g. sane.feeds).
+          # TODO: better design
+          update = rec {
+            _impl.pkgs.sane = mkUpdaters { flakePrefix = [ "update" "_impl" "pkgs" ]; ignore = [ [ "sane" "feeds" ] ]; } [ "sane" ];
+            pkgs = _impl.pkgs.sane;
+            _impl.feeds.sane.feeds = mkUpdaters { flakePrefix = [ "update" "_impl" "feeds" ]; } [ "sane" "feeds" ];
+            feeds = _impl.feeds.sane.feeds;
+          };

          init-feed = {
            type = "app";
            program = "${pkgs.feeds.init-feed}";
          };

-          deploy-lappy = {
-            type = "app";
-            program = ''${deployScript "lappy" "lappy" "switch"}'';
-          };
-          deploy-moby-test = {
-            type = "app";
-            program = ''${deployScript "moby" "moby-hn" "test"}'';
-          };
-          deploy-moby = {
-            type = "app";
-            program = ''${deployScript "moby" "moby-hn" "switch"}'';
-          };
-          deploy-servo = {
-            type = "app";
-            program = ''${deployScript "servo" "servo" "switch"}'';
-          };
+          deploy = {
+            desko       = deployApp "desko"       "desko" "switch";
+            desko-light = deployApp "desko-light" "desko" "switch";
+            lappy       = deployApp "lappy"       "lappy" "switch";
+            lappy-light = deployApp "lappy-light" "lappy" "switch";
+            moby        = deployApp "moby"        "moby"  "switch";
+            moby-light  = deployApp "moby-light"  "moby"  "switch";
+            moby-test   = deployApp "moby"        "moby"  "test";
+            servo       = deployApp "servo"       "servo" "switch";
+
+            # like `nixos-rebuild --flake . switch`
+            self        = deployApp "$(hostname)"       ""      "switch";
+            self-light  = deployApp "$(hostname)-light" ""      "switch";

-          sync-moby = {
-            # copy music from the current device to moby
-            # TODO: should i actually sync from /mnt/servo-media/Music instead of the local drive?
            type = "app";
-            program = builtins.toString (pkgs.writeShellScript "sync-to-moby" ''
-              sudo mount /mnt/moby-home
-              ${pkgs.sane-scripts.sync-music}/bin/sane-sync-music ~/Music /mnt/moby-home/Music
+            program = builtins.toString (pkgs.writeShellScript "deploy-all" ''
+              nix run '.#deploy.lappy'
+              nix run '.#deploy.moby'
+              nix run '.#deploy.desko'
+              nix run '.#deploy.servo'
+            '');
+          };
+          preDeploy = {
+            # build the host and copy the runtime closure to that host, but don't activate it.
+            desko       = deployApp "desko"       "desko" null;
+            desko-light = deployApp "desko-light" "desko" null;
+            lappy       = deployApp "lappy"       "lappy" null;
+            lappy-light = deployApp "lappy-light" "lappy" null;
+            moby        = deployApp "moby"        "moby"  null;
+            moby-light  = deployApp "moby-light"  "moby"  null;
+            servo       = deployApp "servo"       "servo" null;
+            type = "app";
+            program = builtins.toString (pkgs.writeShellScript "predeploy-all" ''
+              # copy the -light variants first; this might be run while waiting on a full build. or the full build failed.
+              nix run '.#preDeploy.moby-light' -- "$@"
+              nix run '.#preDeploy.lappy-light' -- "$@"
+              nix run '.#preDeploy.desko-light' -- "$@"
+              nix run '.#preDeploy.lappy' -- "$@"
+              nix run '.#preDeploy.servo' -- "$@"
+              nix run '.#preDeploy.moby' -- "$@"
+              nix run '.#preDeploy.desko' -- "$@"
            '');
          };

-          sync-lappy = {
+          sync = {
+            type = "app";
+            program = builtins.toString (pkgs.writeShellScript "sync-all" ''
+              RC_lappy=$(nix run '.#sync.lappy' -- "$@")
+              RC_moby=$(nix run '.#sync.moby' -- "$@")
+              RC_desko=$(nix run '.#sync.desko' -- "$@")
+
+              echo "lappy: $RC_lappy"
+              echo "moby: $RC_moby"
+              echo "desko: $RC_desko"
+            '');
+          };
+
+          sync.desko = {
+            # copy music from servo to desko
+            # can run this from any device that has ssh access to desko and servo
+            type = "app";
+            program = builtins.toString (pkgs.writeShellScript "sync-to-desko" ''
+              sudo mount /mnt/desko/home
+              ${pkgs.sane-scripts.sync-music}/bin/sane-sync-music --compat /mnt/servo/media/Music /mnt/desko/home/Music "$@"
+            '');
+          };
+
+          sync.lappy = {
            # copy music from servo to lappy
-            # can run this from any device that has ssh access to lappy
+            # can run this from any device that has ssh access to lappy and servo
            type = "app";
            program = builtins.toString (pkgs.writeShellScript "sync-to-lappy" ''
-              sudo mount /mnt/lappy-home
-              ${pkgs.sane-scripts.sync-music}/bin/sane-sync-music /mnt/servo-media/Music /mnt/lappy-home/Music
+              sudo mount /mnt/lappy/home
+              ${pkgs.sane-scripts.sync-music}/bin/sane-sync-music --compress --compat /mnt/servo/media/Music /mnt/lappy/home/Music "$@"
+            '');
+          };
+
+          sync.moby = {
+            # copy music from servo to moby
+            # can run this from any device that has ssh access to moby and servo
+            type = "app";
+            program = builtins.toString (pkgs.writeShellScript "sync-to-moby" ''
+              sudo mount /mnt/moby/home
+              sudo mount /mnt/desko/home
+              ${pkgs.rsync}/bin/rsync -arv --exclude servo-macros /mnt/moby/home/Pictures/ /mnt/desko/home/Pictures/moby/
+              # N.B.: limited by network/disk -> reduce job count to improve pause/resume behavior
+              ${pkgs.sane-scripts.sync-music}/bin/sane-sync-music --compress --compat --jobs 4 /mnt/servo/media/Music /mnt/moby/home/Music "$@"
            '');
          };

@@ -396,12 +510,12 @@
            program = builtins.toString (pkgs.writeShellScript "check-all" ''
              nix run '.#check.nur'
              RC0=$?
-              nix run '.#check.host-configs'
+              nix run '.#check.hostConfigs'
              RC1=$?
              nix run '.#check.rescue'
              RC2=$?
              echo "nur: $RC0"
-              echo "host-configs: $RC1"
+              echo "hostConfigs: $RC1"
              echo "rescue: $RC2"
              exit $(($RC0 | $RC1 | $RC2))
            '');
@@ -418,32 +532,59 @@
                --option restrict-eval true \
                --option allow-import-from-derivation true \
                --drv-path --show-trace \
-                -I nixpkgs=$(nix-instantiate --find-file nixpkgs) \
+                -I nixpkgs=${nixpkgs-unpatched} \
                -I ../../ \
                | tee  # tee to prevent interactive mode
            '');
          };

-          check.host-configs = {
+          check.hostConfigs = {
            type = "app";
            program = let
-              checkHost = host: ''
-                nix build -v '.#nixosConfigurations.${host}.config.system.build.toplevel' --out-link ./result-${host} -j2 $@
-                RC_${host}=$?
+              checkHost = host: let
+                shellHost = pkgs.lib.replaceStrings [ "-" ] [ "_" ] host;
+              in ''
+                nix build -v '.#nixosConfigurations.${host}.config.system.build.toplevel' --out-link ./result-${host} -j2 "$@"
+                RC_${shellHost}=$?
              '';
            in builtins.toString (pkgs.writeShellScript
              "check-host-configs"
              ''
+                # build minimally-usable hosts first, then their full image.
+                # this gives me a minimal image i can deploy or copy over, early.
+                ${checkHost "desko-light"}
+                ${checkHost "moby-light"}
+                ${checkHost "lappy-light"}
+
                ${checkHost "desko"}
                ${checkHost "lappy"}
                ${checkHost "servo"}
                ${checkHost "moby"}
                ${checkHost "rescue"}
+
+                # still want to build the -light variants first so as to avoid multiple simultaneous webkitgtk builds
+                ${checkHost "desko-light-next"}
+                ${checkHost "moby-light-next"}
+
+                ${checkHost "desko-next"}
+                ${checkHost "lappy-next"}
+                ${checkHost "servo-next"}
+                ${checkHost "moby-next"}
+                ${checkHost "rescue-next"}
+
                echo "desko: $RC_desko"
                echo "lappy: $RC_lappy"
                echo "servo: $RC_servo"
                echo "moby: $RC_moby"
                echo "rescue: $RC_rescue"
+
+                echo "desko-next: $RC_desko_next"
+                echo "lappy-next: $RC_lappy_next"
+                echo "servo-next: $RC_servo_next"
+                echo "moby-next: $RC_moby_next"
+                echo "rescue-next: $RC_rescue_next"
+
+                # i don't really care if the -next hosts fail. i build them mostly to keep the cache fresh/ready
                exit $(($RC_desko | $RC_lappy | $RC_servo | $RC_moby | $RC_rescue))
              ''
            );
--- a/hosts/by-name/desko/default.nix
+++ b/hosts/by-name/desko/default.nix
@@ -9,25 +9,34 @@
  # services.distccd.enable = true;
  # sane.programs.distcc.enableFor.user.guest = true;

+  # TODO: remove emulation, but need to fix nixos-rebuild to moby for that.
+  # sane.roles.build-machine.emulation = true;
+
  sops.secrets.colin-passwd.neededForUsers = true;

+  sane.ports.openFirewall = true;  # for e.g. nix-serve
+
  sane.roles.build-machine.enable = true;
-  sane.roles.ac = true;
  sane.roles.client = true;
  sane.roles.dev-machine = true;
+  sane.roles.pc = true;
  sane.services.wg-home.enable = true;
  sane.services.wg-home.ip = config.sane.hosts.by-name."desko".wg-home.ip;
  sane.services.duplicity.enable = true;
  sane.services.nixserve.secretKeyFile = config.sops.secrets.nix_serve_privkey.path;

-  sane.gui.sway.enable = true;
+  sane.nixcache.substituters.desko = false;
+  sane.nixcache.remote-builders.desko = false;
+
+  sane.programs.sway.enableFor.user.colin = true;
  sane.programs.iphoneUtils.enableFor.user.colin = true;
  sane.programs.steam.enableFor.user.colin = true;

-  sane.programs.guiApps.suggestedPrograms = [ "desktopGuiApps" ];
-  sane.programs.consoleUtils.suggestedPrograms = [ "consoleMediaUtils" "desktopConsoleUtils" ];
  # sane.programs.devPkgs.enableFor.user.colin = true;

+  sane.programs."gnome.geary".config.autostart = true;
+  sane.programs.signal-desktop.config.autostart = true;
+
  boot.loader.efi.canTouchEfiVariables = false;
  sane.image.extraBootFiles = [ pkgs.bootpart-uefi-x86_64 ];

--- a/hosts/by-name/desko/fs.nix
+++ b/hosts/by-name/desko/fs.nix
@@ -1,14 +1,12 @@
 { ... }:

 {
-  sane.persist.root-on-tmpfs = true;
  # increase /tmp space (defaults to 50% of RAM) for building large nix things.
  # a cross-compiled kernel, particularly, will easily use 30+GB of tmp
  fileSystems."/tmp".options = [ "size=64G" ];

  fileSystems."/nix" = {
-    # device = "/dev/disk/by-uuid/985a0a32-da52-4043-9df7-615adec2e4ff";
-    device = "/dev/disk/by-uuid/0ab0770b-7734-4167-88d9-6e4e20bb2a56";
+    device = "/dev/disk/by-uuid/845d85bf-761d-431b-a406-e6f20909154f";
    fsType = "btrfs";
    options = [
      "compress=zstd"
@@ -17,8 +15,7 @@
  };

  fileSystems."/boot" = {
-    # device = "/dev/disk/by-uuid/CAA7-E7D2";
-    device = "/dev/disk/by-uuid/41B6-BAEF";
+    device = "/dev/disk/by-uuid/5049-9AFD";
    fsType = "vfat";
  };
 }
--- a/hosts/by-name/lappy/default.nix
+++ b/hosts/by-name/lappy/default.nix
@@ -7,19 +7,18 @@

  sane.roles.client = true;
  sane.roles.dev-machine = true;
+  sane.roles.pc = true;
  sane.services.wg-home.enable = true;
  sane.services.wg-home.ip = config.sane.hosts.by-name."lappy".wg-home.ip;

  # sane.guest.enable = true;
-  sane.gui.sway.enable = true;
  boot.loader.efi.canTouchEfiVariables = false;
  sane.image.extraBootFiles = [ pkgs.bootpart-uefi-x86_64 ];

-  sane.programs.guiApps.suggestedPrograms = [
-    "desktopGuiApps"
-    "stepmania"
-  ];
-  sane.programs.consoleUtils.suggestedPrograms = [ "consoleMediaUtils" "desktopConsoleUtils" ];
+  sane.programs.sway.enableFor.user.colin = true;
+  sane.programs."gnome.geary".config.autostart = true;
+  sane.programs.signal-desktop.config.autostart = true;
+  sane.programs.stepmania.enableFor.user.colin = true;

  sops.secrets.colin-passwd.neededForUsers = true;

--- a/hosts/by-name/lappy/fs.nix
+++ b/hosts/by-name/lappy/fs.nix
@@ -1,8 +1,6 @@
 { ... }:

 {
-  sane.persist.root-on-tmpfs = true;
-
  fileSystems."/nix" = {
    device = "/dev/disk/by-uuid/75230e56-2c69-4e41-b03e-68475f119980";
    fsType = "btrfs";
@@ -16,24 +14,4 @@
    device = "/dev/disk/by-uuid/BD79-D6BB";
    fsType = "vfat";
  };
-
-  # fileSystems."/nix" = {
-  #   device = "/dev/disk/by-uuid/5a7fa69c-9394-8144-a74c-6726048b129f";
-  #   fsType = "btrfs";
-  # };
-
-  # fileSystems."/boot" = {
-  #   device = "/dev/disk/by-uuid/4302-1685";
-  #   fsType = "vfat";
-  # };
-
-  # fileSystems."/" = {
-  #   device = "none";
-  #   fsType = "tmpfs";
-  #   options = [
-  #     "mode=755"
-  #     "size=1G"
-  #     "defaults"
-  #   ];
-  # };
 }
--- a/hosts/by-name/lappy/polyfill.nix
+++ b/hosts/by-name/lappy/polyfill.nix
@@ -3,7 +3,6 @@
 { pkgs, ... }:
 {
  sane.gui.sxmo = {
-    greeter = "greetd-sway-gtkgreet";
    noidle = true;  #< power button requires 1s hold, which makes it impractical to be dealing with.
    settings = {
      # XXX: make sure the user is part of the `input` group!
@@ -22,7 +21,6 @@
      # the device type informs (at least):
      # - SXMO_WIFI_MODULE
      # - SXMO_RTW_SCAN_INTERVAL
-      # - SXMO_SYS_FILES
      # - SXMO_TOUCHSCREEN_ID
      # - SXMO_MONITOR
      # - SXMO_ALSA_CONTROL_NAME
@@ -33,7 +31,7 @@
      #   and so it just wouldn't handle any button inputs (sxmo_hook_inputhandler.sh not on path)
      SXMO_DEVICE_NAME = "three_button_touchscreen";
    };
-    package = (pkgs.sxmo-utils-latest.override { preferSystemd = true; }).overrideAttrs (base: {
+    package = (pkgs.sxmo-utils.override { preferSystemd = true; }).overrideAttrs (base: {
      postPatch = (base.postPatch or "") + ''
        # after volume-button navigation mode, restore full keyboard functionality
        cp ${./xkb_mobile_normal_buttons} ./configs/xkb/xkb_mobile_normal_buttons
--- a/hosts/by-name/moby/default.nix
+++ b/hosts/by-name/moby/default.nix
@@ -20,27 +20,28 @@
  ];

  sane.roles.client = true;
+  sane.roles.handheld = true;
  sane.zsh.showDeadlines = false;  # unlikely to act on them when in shell
  sane.services.wg-home.enable = true;
  sane.services.wg-home.ip = config.sane.hosts.by-name."moby".wg-home.ip;

+  # for some reason desko -> moby deploys are super flaky when desko is also a nixcache (not true of desko -> lappy deploys, though!)
+  # > unable to download 'http://desko:5001/<hash>.narinfo': Server returned nothing (no headers, no data) (52)
+  sane.nixcache.substituters.desko = false;
+
  # XXX colin: phosh doesn't work well with passwordless login,
  # so set this more reliable default password should anything go wrong
  users.users.colin.initialPassword = "147147";
-  services.getty.autologinUser = "root";  # allows for emergency maintenance?
+  # services.getty.autologinUser = "root";  # allows for emergency maintenance?

  sops.secrets.colin-passwd.neededForUsers = true;

  sane.gui.sxmo.enable = true;
-  sane.programs.guiApps.suggestedPrograms = [ "handheldGuiApps" ];
  # sane.programs.consoleUtils.enableFor.user.colin = false;
  # sane.programs.guiApps.enableFor.user.colin = false;
  sane.programs.blueberry.enableFor.user.colin = false;  # bluetooth manager: doesn't cross compile!
  sane.programs.mercurial.enableFor.user.colin = false;  # does not cross compile
-  sane.programs.sequoia.enableFor.user.colin = false;
-  sane.programs.tuiApps.enableFor.user.colin = false;  # visidata, others, don't compile well
-  # disabled for faster deploys
-  sane.programs.soundconverter.enableFor.user.colin = false;
+  sane.programs.nvme-cli.enableFor.system = false;  # does not cross compile (libhugetlbfs)

  # enabled for easier debugging
  sane.programs.eg25-control.enableFor.user.colin = true;
@@ -48,6 +49,8 @@

  # sane.programs.ntfy-sh.config.autostart = true;
  sane.programs.dino.config.autostart = true;
+  # sane.programs.signal-desktop.config.autostart = true;  # TODO: enable once electron stops derping.
+  # sane.programs."gnome.geary".config.autostart = true;
  # sane.programs.calls.config.autostart = true;
  sane.programs.mpv.config.vo = "wlshm";  #< see hosts/common/programs/mpv.nix for details

@@ -55,7 +58,6 @@
  # HACK/TODO: make `programs.P.env.VAR` behave according to `mime.priority`
  sane.programs.firefox.env = lib.mkForce {};
  sane.programs.epiphany.env.BROWSER = "epiphany";
-  sane.programs.firefox.enableFor.user.colin = false;  # use epiphany instead

  # note the .conf.d approach: using ~/.config/pipewire/pipewire.conf directly breaks all audio,
  # presumably because that deletes the defaults entirely whereas the .conf.d approach selectively overrides defaults
--- a/hosts/by-name/moby/fs.nix
+++ b/hosts/by-name/moby/fs.nix
@@ -1,7 +1,6 @@
 { ... }:

 {
-  sane.persist.root-on-tmpfs = true;
  fileSystems."/nix" = {
    device = "/dev/disk/by-uuid/1f1271f8-53ce-4081-8a29-60a4a6b5d6f9";
    fsType = "btrfs";
--- a/hosts/by-name/moby/kernel.nix
+++ b/hosts/by-name/moby/kernel.nix
@@ -74,6 +74,7 @@ in
    # without this some GUI apps fail: `DRM_IOCTL_MODE_CREATE_DUMB failed: Cannot allocate memory`
    # this is because they can't allocate enough video ram.
    # see related nixpkgs issue: <https://github.com/NixOS/nixpkgs/issues/260222>
+    # TODO(2023/12/03): remove once mesa 23.3.1 lands: <https://github.com/NixOS/nixpkgs/pull/265740>
    #
    # the default CMA seems to be 32M.
    # i was running fine with 256MB from 2022/07-ish through 2022/12-ish, but then the phone quit reliably coming back from sleep (phosh): maybe a memory leak?
--- a/hosts/by-name/rescue/fs.nix
+++ b/hosts/by-name/rescue/fs.nix
@@ -1,7 +1,7 @@
 { ... }:

 {
-  fileSystems."/" = {
+  fileSystems."/nix" = {
    device = "/dev/disk/by-uuid/44445555-6666-7777-8888-999900001111";
    fsType = "ext4";
  };
--- a/hosts/by-name/servo/default.nix
+++ b/hosts/by-name/servo/default.nix
@@ -14,12 +14,11 @@
    signaldctl.enableFor.user.colin = true;
  };

-  sane.roles.ac = true;
  sane.roles.build-machine.enable = true;
-  sane.roles.build-machine.emulation = false;
  sane.zsh.showDeadlines = false;  # ~/knowledge doesn't always exist
  sane.programs.consoleUtils.suggestedPrograms = [
-    "desktopConsoleUtils"
+    "consoleMediaUtils"  # notably, for go2tv / casting
+    "pcConsoleUtils"
    "sane-scripts.stop-all-servo"
  ];
  sane.services.dyn-dns.enable = true;
@@ -30,6 +29,8 @@
  sane.services.wg-home.ip = config.sane.hosts.by-name."servo".wg-home.ip;
  sane.nixcache.substituters.servo = false;
  sane.nixcache.substituters.desko = false;
+  sane.nixcache.remote-builders.desko = false;
+  sane.nixcache.remote-builders.servo = false;
  # sane.services.duplicity.enable = true;  # TODO: re-enable after HW upgrade

  # automatically log in at the virtual consoles.
--- a/hosts/by-name/servo/fs.nix
+++ b/hosts/by-name/servo/fs.nix
@@ -1,7 +1,58 @@
+# zfs docs:
+# - <https://nixos.wiki/wiki/ZFS>
+# - <repo:nixos/nixpkgs:nixos/modules/tasks/filesystems/zfs.nix>
+#
+# zfs check health: `zpool status`
+#
+# zfs pool creation (requires `boot.supportedFilesystems = [ "zfs" ];`
+# - 1. identify disk IDs: `ls -l /dev/disk/by-id`
+# - 2. pool these disks: `zpool create -f -m legacy pool raidz ata-ST4000VN008-2DR166_WDH0VB45 ata-ST4000VN008-2DR166_WDH17616 ata-ST4000VN008-2DR166_WDH0VC8Q ata-ST4000VN008-2DR166_WDH17680`
+#   - legacy documented: <https://superuser.com/questions/790036/what-is-a-zfs-legacy-mount-point>
+#
+# import pools: `zpool import pool`
+# show zfs datasets: `zfs list` (will be empty if haven't imported)
+# show zfs properties (e.g. compression): `zfs get all pool`
+# set zfs properties: `zfs set compression=on pool`
 { ... }:

 {
-  sane.persist.root-on-tmpfs = true;
+  # hostId: not used for anything except zfs guardrail?
+  #   [hex(ord(x)) for x in 'serv']
+  networking.hostId = "73657276";
+  boot.supportedFilesystems = [ "zfs" ];
+  # boot.zfs.enabled = true;
+  boot.zfs.forceImportRoot = false;
+  # scrub all zfs pools weekly:
+  services.zfs.autoScrub.enable = true;
+  boot.extraModprobeConfig = ''
+    # ZFS likes to use half the ram for its own cache and let the kernel push everything else to swap.
+    # so, reduce its cache size
+    # see: <https://askubuntu.com/a/1290387>
+    # see: <https://serverfault.com/a/1119083>
+    # see: <https://openzfs.github.io/openzfs-docs/Performance%20and%20Tuning/Module%20Parameters.html#zfs-arc-max>
+    # for all tunables, see: `man 4 zfs`
+    # to update these parameters without rebooting:
+    # - `echo '4294967296' | sane-sudo-redirect /sys/module/zfs/parameters/zfs_arc_max`
+    options zfs zfs_arc_max=4294967296
+  '';
+  # to be able to mount the pool like this, make sure to tell zfs to NOT manage it itself.
+  # otherwise local-fs.target will FAIL and you will be dropped into a rescue shell.
+  # - `zfs set mountpoint=legacy pool`
+  # if done correctly, the pool can be mounted before this `fileSystems` entry is created:
+  # - `sudo mount -t zfs pool /mnt/persist/pool`
+  fileSystems."/mnt/pool" = {
+    device = "pool";
+    fsType = "zfs";
+  };
+  # services.zfs.zed = ... # TODO: zfs can send me emails when disks fail
+  sane.programs.sysadminUtils.suggestedPrograms = [ "zfs" ];
+
+  sane.persist.stores."ext" = {
+    origin = "/mnt/pool/persist";
+    storeDescription = "external HDD storage";
+    defaultMethod = "bind";  #< TODO: change to "symlink"?
+  };
+
  # increase /tmp space (defaults to 50% of RAM) for building large nix things.
  # even the stock `nixpkgs.linux` consumes > 16 GB of tmp
  fileSystems."/tmp".options = [ "size=32G" ];
@@ -21,7 +72,7 @@
  };

  # slow, external storage (for archiving, etc)
-  fileSystems."/mnt/persist/ext" = {
+  fileSystems."/mnt/usb-hdd" = {
    device = "/dev/disk/by-uuid/aa272cff-0fcc-498e-a4cb-0d95fb60631b";
    fsType = "btrfs";
    options = [
@@ -29,22 +80,18 @@
      "defaults"
    ];
  };
-
-  sane.persist.stores."ext" = {
-    origin = "/mnt/persist/ext/persist";
-    storeDescription = "external HDD storage";
-  };
-  sane.fs."/mnt/persist/ext".mount = {};
+  sane.fs."/mnt/usb-hdd".mount = {};

  sane.persist.sys.byStore.plaintext = [
    # TODO: this is overly broad; only need media and share directories to be persisted
-    { user = "colin"; group = "users"; path = "/var/lib/uninsane"; }
+    { user = "colin"; group = "users"; path = "/var/lib/uninsane"; method = "bind"; }
  ];
  # force some problematic directories to always get correct permissions:
  sane.fs."/var/lib/uninsane/media".dir.acl = {
    user = "colin"; group = "media"; mode = "0775";
  };
  sane.fs."/var/lib/uninsane/media/archive".dir = {};
+  # this is file.text instead of symlink.text so that it may be read over a remote mount (where consumers might not have any /nix/store/.../README.md path)
  sane.fs."/var/lib/uninsane/media/archive/README.md".file.text = ''
    this directory is for media i wish to remove from my library,
    but keep for a short time in case i reverse my decision.
@@ -63,13 +110,14 @@
  sane.fs."/var/lib/uninsane/media/Videos/Film".dir = {};
  sane.fs."/var/lib/uninsane/media/Videos/Shows".dir = {};
  sane.fs."/var/lib/uninsane/media/Videos/Talks".dir = {};
+  # this is file.text instead of symlink.text so that it may be read over a remote mount (where consumers might not have any /nix/store/.../README.md path)
  sane.fs."/var/lib/uninsane/datasets/README.md".file.text = ''
    this directory may seem redundant with ../media/datasets. it isn't.
    this directory exists on SSD, allowing for speedy access to specific datasets when necessary.
    the contents should be a subset of what's in ../media/datasets.
  '';
  # make sure large media is stored to the HDD
-  sane.persist.sys.ext = [
+  sane.persist.sys.byStore.ext = [
    {
      user = "colin";
      group = "users";
--- a/hosts/by-name/servo/net.nix
+++ b/hosts/by-name/servo/net.nix
@@ -24,61 +24,12 @@ in
    sane.ports.openFirewall = true;
    sane.ports.openUpnp = true;

-    # view refused packets with: `sudo journalctl -k`
-    # networking.firewall.logRefusedPackets = true;
-
-    # The global useDHCP flag is deprecated, therefore explicitly set to false here.
-    # Per-interface useDHCP will be mandatory in the future, so this generated config
-    # replicates the default behaviour.
-    networking.useDHCP = false;
-    networking.interfaces.eth0.useDHCP = true;
-    # XXX colin: probably don't need this. wlan0 won't be populated unless i touch a value in networking.interfaces.wlan0
-    networking.wireless.enable = false;
-
-    # this is needed to forward packets from the VPN to the host
-    boot.kernel.sysctl."net.ipv4.ip_forward" = 1;
-
    # unless we add interface-specific settings for each VPN, we have to define nameservers globally.
    # networking.nameservers = [
    #   "1.1.1.1"
    #   "9.9.9.9"
    # ];

-    # use systemd's stub resolver.
-    # /etc/resolv.conf isn't sophisticated enough to use different servers per net namespace (or link).
-    # instead, running the stub resolver on a known address in the root ns lets us rewrite packets
-    # in the ovnps namespace to use the provider's DNS resolvers.
-    # a weakness is we can only query 1 NS at a time (unless we were to clone the packets?)
-    # there also seems to be some cache somewhere that's shared between the two namespaces.
-    # i think this is a libc thing. might need to leverage proper cgroups to _really_ kill it.
-    # - getent ahostsv4 www.google.com
-    # - try fix: <https://serverfault.com/questions/765989/connect-to-3rd-party-vpn-server-but-dont-use-it-as-the-default-route/766290#766290>
-    services.resolved.enable = true;
-    # without DNSSEC:
-    # - dig matrix.org => works
-    # - curl https://matrix.org => works
-    # with default DNSSEC:
-    # - dig matrix.org => works
-    # - curl https://matrix.org => fails
-    # i don't know why. this might somehow be interfering with the DNS run on this device (trust-dns)
-    services.resolved.dnssec = "false";
-    networking.nameservers = [
-      # use systemd-resolved resolver
-      # full resolver (which understands /etc/hosts) lives on 127.0.0.53
-      # stub resolver (just forwards upstream) lives on 127.0.0.54
-      "127.0.0.53"
-    ];
-
-    # nscd -- the Name Service Caching Daemon -- caches DNS query responses
-    # in a way that's unaware of my VPN routing, so routes are frequently poor against
-    # services which advertise different IPs based on geolocation.
-    # nscd claims to be usable without a cache, but in practice i can't get it to not cache!
-    # nsncd is the Name Service NON-Caching Daemon. it's a drop-in that doesn't cache;
-    # this is OK on the host -- because systemd-resolved caches. it's probably sub-optimal
-    # in the netns and we query upstream DNS more often than needed. hm.
-    # TODO: run a separate recursive resolver in each namespace.
-    services.nscd.enableNsncd = true;
-
    # services.resolved.extraConfig = ''
    #   # docs: `man resolved.conf`
    #   # DNS servers to use via the `wg-ovpns` interface.
--- a/hosts/by-name/servo/services/calibre.nix
+++ b/hosts/by-name/servo/services/calibre.nix
@@ -13,7 +13,7 @@ in
 lib.mkIf false
 {
  sane.persist.sys.byStore.plaintext = [
-    { inherit user group; mode = "0700"; path = svc-dir; }
+    { inherit user group; mode = "0700"; path = svc-dir; method = "bind"; }
  ];

  services.calibre-web.enable = true;
--- a/hosts/by-name/servo/services/cryptocurrencies/bitcoin.nix
+++ b/hosts/by-name/servo/services/cryptocurrencies/bitcoin.nix
@@ -0,0 +1,83 @@
+# as of 2023/12/02: complete blockchain is 530 GiB (on-disk size may be larger)
+#
+# ports:
+# - 8333: for node-to-node communications
+# - 8332: rpc (client-to-node)
+#
+# rpc setup:
+# - generate a password
+#   - use: <https://github.com/bitcoin/bitcoin/blob/master/share/rpcauth/rpcauth.py>
+#     (rpcauth.py is not included in the `'.#bitcoin'` package result)
+#   - `wget https://raw.githubusercontent.com/bitcoin/bitcoin/master/share/rpcauth/rpcauth.py`
+#   - `python ./rpcauth.py colin`
+#   - copy the hash here. it's SHA-256, so safe to be public.
+#   - add "rpcuser=colin" and "rpcpassword=<output>" to secrets/servo/bitcoin.conf  (i.e. ~/.bitcoin/bitcoin.conf)
+#     - bitcoin.conf docs: <https://github.com/bitcoin/bitcoin/blob/master/doc/bitcoin-conf.md>
+# - validate with `bitcoin-cli -netinfo`
+{ config, lib, pkgs, sane-lib, ... }:
+let
+  # wrapper to run bitcoind with the tor onion address as externalip (computed at runtime)
+  _bitcoindWithExternalIp = with pkgs; writeShellScriptBin "bitcoind" ''
+    externalip="$(cat /var/lib/tor/onion/bitcoind/hostname)"
+    exec ${bitcoind}/bin/bitcoind "-externalip=$externalip" "$@"
+  '';
+  # the package i provide to services.bitcoind ends up on system PATH, and used by other tools like clightning.
+  # therefore, even though services.bitcoind only needs `bitcoind` binary, provide all the other bitcoin-related binaries (notably `bitcoin-cli`) as well:
+  bitcoindWithExternalIp = with pkgs; symlinkJoin {
+    name = "bitcoind-with-external-ip";
+    paths = [ _bitcoindWithExternalIp bitcoind ];
+  };
+in
+{
+  sane.persist.sys.byStore.ext = [
+    { user = "bitcoind-mainnet"; group = "bitcoind-mainnet"; path = "/var/lib/bitcoind-mainnet"; method = "bind"; }
+  ];
+
+  # sane.ports.ports."8333" = {
+  #   # this allows other nodes and clients to download blocks from me.
+  #   protocol = [ "tcp" ];
+  #   visibleTo.wan = true;
+  #   description = "colin-bitcoin";
+  # };
+
+  services.tor.relay.onionServices.bitcoind = {
+    version = 3;
+    map = [{
+      # by default tor will route public tor port P to 127.0.0.1:P.
+      # so if this port is the same as clightning would natively use, then no further config is needed here.
+      # see: <https://2019.www.torproject.org/docs/tor-manual.html.en#HiddenServicePort>
+      port = 8333;
+      # target.port; target.addr;  #< set if tor port != clightning port
+    }];
+    # allow "tor" group (i.e. bitcoind-mainnet) to read /var/lib/tor/onion/bitcoind/hostname
+    settings.HiddenServiceDirGroupReadable = true;
+  };
+
+  services.bitcoind.mainnet = {
+    enable = true;
+    package = bitcoindWithExternalIp;
+    rpc.users.colin = {
+      # see docs at top of file for how to generate this
+      passwordHMAC = "30002c05d82daa210550e17a182db3f3$6071444151281e1aa8a2729f75e3e2d224e9d7cac3974810dab60e7c28ffaae4";
+    };
+    extraConfig = ''
+      # don't load the wallet, and disable wallet RPC calls
+      disablewallet=1
+      # proxy all outbound traffic through Tor
+      proxy=127.0.0.1:9050
+    '';
+  };
+
+  users.users.bitcoind-mainnet.extraGroups = [ "tor" ];
+
+  systemd.services.bitcoind-mainnet.serviceConfig.RestartSec = "30s";  #< default is 0
+
+  sane.users.colin.fs.".bitcoin/bitcoin.conf" = sane-lib.fs.wantedSymlinkTo config.sops.secrets."bitcoin.conf".path;
+  sops.secrets."bitcoin.conf" = {
+    mode = "0600";
+    owner = "colin";
+    group = "users";
+  };
+
+  sane.programs.bitcoind.enableFor.user.colin = true;  # for debugging/administration: `bitcoin-cli`
+}
--- a/hosts/by-name/servo/services/cryptocurrencies/clightning-sane/clightning-sane
+++ b/hosts/by-name/servo/services/cryptocurrencies/clightning-sane/clightning-sane
@@ -0,0 +1,766 @@
+#!/usr/bin/env nix-shell
+#!nix-shell -i python3 -p "python3.withPackages (ps: [ ps.pyln-client ])"
+
+# pyln-client docs: <https://github.com/ElementsProject/lightning/tree/master/contrib/pyln-client>
+# terminology:
+# - "scid": "Short Channel ID", e.g. 123456x7890x0
+#   from this id, we can locate the actual channel, its peers, and its parameters
+
+import argparse
+import logging
+import math
+import sys
+import time
+
+from concurrent.futures import ThreadPoolExecutor
+from dataclasses import dataclass
+from enum import Enum
+
+from pyln.client import LightningRpc, Millisatoshi, RpcError
+
+logger = logging.getLogger(__name__)
+
+RPC_FILE = "/var/lib/clightning/bitcoin/lightning-rpc"
+# CLTV (HLTC delta) of the final hop
+# set this too low and you might get inadvertent channel closures (?)
+CLTV = 18
+
+# for every sequentally failed transaction, delay this much before trying again.
+# note that the initial route building process can involve 10-20 "transient" failures, as it discovers dead channels.
+TX_FAIL_BACKOFF = 0.8
+MAX_SEQUENTIAL_JOB_FAILURES = 200
+
+class LoopError(Enum):
+    """ error when trying to loop sats, or when unable to calculate a route for the loop """
+    TRANSIENT = "TRANSIENT"  # try again, we'll maybe find a different route
+    NO_ROUTE = "NO_ROUTE"
+
+class RouteError(Enum):
+    """ error when calculated a route """
+    HAS_BASE_FEE = "HAS_BASE_FEE"
+    NO_ROUTE = "NO_ROUTE"
+
+class Metrics:
+    looped_msat: int = 0
+    sendpay_fail: int = 0
+    sendpay_succeed: int = 0
+    own_bad_channel: int = 0
+    no_route: int = 0
+    in_ch_unsatisfiable: int = 0
+
+    def __repr__(self) -> str:
+        return f"looped:{self.looped_msat}, tx:{self.sendpay_succeed}, tx_fail:{self.sendpay_fail}, own_bad_ch:{self.own_bad_channel}, no_route:{self.no_route}, in_ch_restricted:{self.in_ch_unsatisfiable}"
+
+@dataclass
+class TxBounds:
+    max_msat: int
+    min_msat: int = 0
+
+    def __repr__(self) -> str:
+        return f"TxBounds({self.min_msat} <= msat <= {self.max_msat})"
+
+    def is_satisfiable(self) -> bool:
+        return self.min_msat <= self.max_msat
+
+    def raise_max_to_be_satisfiable(self) -> "Self":
+        if self.max_msat < self.min_msat:
+            logger.debug(f"raising max_msat to be consistent: {self.max_msat} -> {self.min_msat}")
+            return TxBounds(self.min_msat, self.min_msat)
+        return TxBounds(min_msat=self.min_msat, max_msat=self.max_msat)
+
+    def intersect(self, other: "TxBounds") -> "Self":
+        return TxBounds(
+            min_msat=max(self.min_msat, other.min_msat),
+            max_msat=min(self.max_msat, other.max_msat),
+        )
+
+    def restrict_to_htlc(self, ch: "LocalChannel", why: str = "") -> "Self":
+        """
+        apply min/max HTLC size restrictions of the given channel.
+        """
+        if ch:
+            why = why or ch.directed_scid_to_me
+        if why: why = f"{why}: "
+
+        new_min, new_max = self.min_msat, self.max_msat
+        if ch.htlc_minimum_to_me > self.min_msat:
+            new_min = ch.htlc_minimum_to_me
+            logger.debug(f"{why}raising min_msat due to HTLC requirements: {self.min_msat} -> {new_min}")
+        if ch.htlc_maximum_to_me < self.max_msat:
+            new_max = ch.htlc_maximum_to_me
+            logger.debug(f"{why}lowering max_msat due to HTLC requirements: {self.max_msat} -> {new_max}")
+        return TxBounds(min_msat=new_min, max_msat=new_max)
+
+    def restrict_to_zero_fees(self, ch: "LocalChannel"=None, base: int=0, ppm: int=0, why:str = "") -> "Self":
+        """
+        restrict tx size such that PPM fees are zero.
+        if the channel has a base fee, then `max_msat` is forced to 0.
+        """
+        if ch:
+            why = why or ch.directed_scid_to_me
+            self = self.restrict_to_zero_fees(base=ch.to_me["base_fee_millisatoshi"], ppm=ch.to_me["fee_per_millionth"], why=why)
+
+        if why: why = f"{why}: "
+
+        new_max = self.max_msat
+        ppm_max = math.ceil(1000000 / ppm) - 1 if ppm != 0 else new_max
+        if ppm_max < new_max:
+            logger.debug(f"{why}decreasing max_msat due to fee ppm: {new_max} -> {ppm_max}")
+            new_max = ppm_max
+
+        if base != 0:
+            logger.debug(f"{why}free route impossible: channel has base fees")
+            new_max = 0
+
+        return TxBounds(min_msat=self.min_msat, max_msat=new_max)
+
+
+class LocalChannel:
+    def __init__(self, channels: list, rpc: "RpcHelper"):
+        assert 0 < len(channels) <= 2, f"unexpected: channel count: {channels}"
+        out = None
+        in_ = None
+        for c in channels:
+            if c["source"] == rpc.self_id:
+                assert out is None, f"unexpected: multiple channels from self: {channels}"
+                out = c
+            if c["destination"] == rpc.self_id:
+                assert in_ is None, f"unexpected: multiple channels to self: {channels}"
+                in_ = c
+
+        # assert out is not None, f"no channel from self: {channels}"
+        # assert in_ is not None, f"no channel to self: {channels}"
+
+        if out and in_:
+            assert out["destination"] == in_["source"], f"channel peers are asymmetric?! {channels}"
+            assert out["short_channel_id"] == in_["short_channel_id"], f"channel ids differ?! {channels}"
+
+        self.from_me = out
+        self.to_me = in_
+        self.remote_node = rpc.node(self.remote_peer)
+        self.peer_ch = rpc.peerchannel(self.scid, self.remote_peer)
+        self.forwards_from_me = rpc.rpc.listforwards(out_channel=self.scid, status="settled")["forwards"]
+
+    def __repr__(self) -> str:
+        return self.to_str(with_scid=True, with_bal_ratio=True, with_cost=False, with_ppm_theirs=False)
+
+    def to_str(
+        self,
+        with_peer_id:bool = False,
+        with_scid:bool = False,
+        with_bal_msat:bool = False,
+        with_bal_ratio:bool = False,
+        with_cost:bool = False,
+        with_ppm_theirs:bool = False,
+        with_ppm_mine:bool = False,
+        with_profits:bool = True,
+        with_payments:bool = False,
+    ) -> str:
+        base_flag = "*" if not self.online or self.base_fee_to_me != 0 else ""
+        alias = f"({self.remote_alias}){base_flag}"
+        peerid = f" {self.remote_peer}" if with_peer_id else ""
+        scid = f"  scid:{self.scid:>13}" if with_scid else ""
+        bal = f"  S:{int(self.sendable):11}/R:{int(self.receivable):11}" if with_bal_msat else ""
+        ratio = f"  MINE:{(100*self.send_ratio):>8.4f}%" if with_bal_ratio else ""
+        payments = f"  OUT:{int(self.out_fulfilled_msat):>11}/IN:{int(self.in_fulfilled_msat):>11}" if with_payments else ""
+        profits = f"  P$:{int(self.fees_lifetime_mine):>8}" if with_profits else ""
+        cost = f"  COST:{self.opportunity_cost_lent:>8}" if with_cost else ""
+        ppm_theirs = self.ppm_to_me if self.to_me else "N/A"
+        ppm_theirs = f"  PPM_THEIRS:{ppm_theirs:>6}" if with_ppm_theirs else ""
+        ppm_mine = self.ppm_from_me if self.from_me else "N/A"
+        ppm_mine = f"  PPM_MINE:{ppm_mine:>6}" if with_ppm_mine else ""
+        return f"channel{alias:30}{peerid}{scid}{bal}{ratio}{payments}{profits}{cost}{ppm_theirs}{ppm_mine}"
+
+
+    @property
+    def online(self) -> bool:
+        return self.from_me and self.to_me
+
+    @property
+    def remote_peer(self) -> str:
+        if self.from_me:
+            return self.from_me["destination"]
+        else:
+            return self.to_me["source"]
+
+    @property
+    def remote_alias(self) -> str:
+        return self.remote_node["alias"]
+
+    @property
+    def scid(self) -> str:
+        if self.from_me:
+            return self.from_me["short_channel_id"]
+        else:
+            return self.to_me["short_channel_id"]
+
+    @property
+    def htlc_minimum_to_me(self) -> Millisatoshi:
+        return self.to_me["htlc_minimum_msat"]
+
+    @property
+    def htlc_minimum_from_me(self) -> Millisatoshi:
+        return self.from_me["htlc_minimum_msat"]
+
+    @property
+    def htlc_minimum(self) -> Millisatoshi:
+        return max(self.htlc_minimum_to_me, self.htlc_minimum_from_me)
+
+    @property
+    def htlc_maximum_to_me(self) -> Millisatoshi:
+        return self.to_me["htlc_maximum_msat"]
+
+    @property
+    def htlc_maximum_from_me(self) -> Millisatoshi:
+        return self.from_me["htlc_maximum_msat"]
+
+    @property
+    def htlc_maximum(self) -> Millisatoshi:
+        return min(self.htlc_maximum_to_me, self.htlc_maximum_from_me)
+
+    @property
+    def direction_to_me(self) -> int:
+        return self.to_me["direction"]
+
+    @property
+    def direction_from_me(self) -> int:
+        return self.from_me["direction"]
+
+    @property
+    def directed_scid_to_me(self) -> str:
+        return f"{self.scid}/{self.direction_to_me}"
+
+    @property
+    def directed_scid_from_me(self) -> str:
+        return f"{self.scid}/{self.direction_from_me}"
+
+    @property
+    def delay_them(self) -> str:
+        return self.to_me["delay"]
+
+    @property
+    def delay_me(self) -> str:
+        return self.from_me["delay"]
+
+    @property
+    def ppm_to_me(self) -> int:
+        return self.to_me["fee_per_millionth"]
+
+    @property
+    def ppm_from_me(self) -> int:
+        return self.from_me["fee_per_millionth"]
+        # return self.peer_ch["fee_proportional_millionths"]
+
+    @property
+    def base_fee_to_me(self) -> int:
+        return self.to_me["base_fee_millisatoshi"]
+
+    @property
+    def receivable(self) -> int:
+        return self.peer_ch["receivable_msat"]
+
+    @property
+    def sendable(self) -> int:
+        return self.peer_ch["spendable_msat"]
+
+    @property
+    def in_fulfilled_msat(self) -> Millisatoshi:
+        return self.peer_ch["in_fulfilled_msat"]
+
+    @property
+    def out_fulfilled_msat(self) -> Millisatoshi:
+        return self.peer_ch["out_fulfilled_msat"]
+
+    @property
+    def fees_lifetime_mine(self) -> Millisatoshi:
+        return sum(fwd["fee_msat"] for fwd in self.forwards_from_me)
+
+    @property
+    def send_ratio(self) -> float:
+        cap = self.receivable + self.sendable
+        return self.sendable / cap
+
+    @property
+    def opportunity_cost_lent(self) -> int:
+        """ how much msat did we gain by pushing their channel to its current balance? """
+        return int(self.receivable * self.ppm_from_me / 1000000)
+
+class RpcHelper:
+    def __init__(self, rpc: LightningRpc):
+        self.rpc = rpc
+        self.self_id = rpc.getinfo()["id"]
+
+    def localchannel(self, scid: str) -> LocalChannel:
+        listchan = self.rpc.listchannels(scid)
+        # this assertion would probably indicate a typo in the scid
+        assert listchan and listchan.get("channels", []) != [], f"bad listchannels for {scid}: {listchan}"
+        return LocalChannel(listchan["channels"], self)
+
+    def node(self, id: str) -> dict:
+        nodes = self.rpc.listnodes(id)["nodes"]
+        assert len(nodes) == 1, f"unexpected: multiple nodes for {id}: {nodes}"
+        return nodes[0]
+
+    def peerchannel(self, scid: str, peer_id: str) -> dict:
+        peerchannels = self.rpc.listpeerchannels(peer_id)["channels"]
+        channels = [c for c in peerchannels if c["short_channel_id"] == scid]
+        assert len(channels) == 1, f"expected exactly 1 channel, got: {channels}"
+        return channels[0]
+
+    def try_getroute(self, *args, **kwargs) -> dict | None:
+        """ wrapper for getroute which returns None instead of error if no route exists """
+        try:
+            route = self.rpc.getroute(*args, **kwargs)
+        except RpcError as e:
+            logger.debug(f"rpc failed: {e}")
+            return None
+        else:
+            route = route["route"]
+            if route == []: return None
+            return route
+
+class LoopRouter:
+    def __init__(self, rpc: RpcHelper, metrics: Metrics = None):
+        self.rpc = rpc
+        self.metrics = metrics or Metrics()
+        self.bad_channels = []  # list of directed scid
+        self.nonzero_base_channels = []  # list of directed scid
+
+    def drop_caches(self) -> None:
+        logger.info("LoopRouter.drop_caches()")
+        self.bad_channels = []
+
+    def _get_directed_scid(self, scid: str, direction: int) -> dict:
+        channels = self.rpc.rpc.listchannels(scid)["channels"]
+        channels = [c for c in channels if c["direction"] == direction]
+        assert len(channels) == 1, f"expected exactly 1 channel: {channels}"
+        return channels[0]
+
+    def loop_once(self, out_scid: str, in_scid: str, bounds: TxBounds) -> LoopError|int:
+        out_ch = self.rpc.localchannel(out_scid)
+        in_ch = self.rpc.localchannel(in_scid)
+
+        if out_ch.directed_scid_from_me in self.bad_channels or in_ch.directed_scid_to_me in self.bad_channels:
+            logger.info(f"loop {out_scid} -> {in_scid} failed in our own channel")
+            self.metrics.own_bad_channel += 1
+            return LoopError.TRANSIENT
+
+        # bounds = bounds.restrict_to_htlc(out_ch)  # htlc bounds seem to be enforced only in the outward direction
+        bounds = bounds.restrict_to_htlc(in_ch)
+        bounds = bounds.restrict_to_zero_fees(in_ch)
+        if not bounds.is_satisfiable():
+            self.metrics.in_ch_unsatisfiable += 1
+            return LoopError.NO_ROUTE
+
+        logger.debug(f"route with bounds {bounds}")
+        route = self.route(out_ch, in_ch, bounds)
+        logger.debug(f"route: {route}")
+        if route == RouteError.NO_ROUTE:
+            self.metrics.no_route += 1
+            return LoopError.NO_ROUTE
+        elif route == RouteError.HAS_BASE_FEE:
+            # try again with a different route
+            return LoopError.TRANSIENT
+
+        amount_msat = route[0]["amount_msat"]
+        invoice_id = f"loop-{time.time():.6f}".replace(".", "_")
+        invoice_desc = f"bal {out_scid}:{in_scid}"
+        invoice = self.rpc.rpc.invoice("any", invoice_id, invoice_desc)
+        logger.debug(f"invoice: {invoice}")
+
+        payment = self.rpc.rpc.sendpay(route, invoice["payment_hash"], invoice_id, amount_msat, invoice["bolt11"], invoice["payment_secret"])
+        logger.debug(f"sent: {payment}")
+
+        try:
+            wait = self.rpc.rpc.waitsendpay(invoice["payment_hash"])
+            logger.debug(f"result: {wait}")
+        except RpcError as e:
+            self.metrics.sendpay_fail += 1
+            err_data = e.error["data"]
+            err_scid, err_dir = err_data["erring_channel"], err_data["erring_direction"]
+            err_directed_scid = f"{err_scid}/{err_dir}"
+            logger.debug(f"ch failed, adding to excludes: {err_directed_scid}; {e.error}")
+            self.bad_channels.append(err_directed_scid)
+            return LoopError.TRANSIENT
+        else:
+            self.metrics.sendpay_succeed += 1
+            self.metrics.looped_msat += int(amount_msat)
+            return int(amount_msat)
+
+    def route(self, out_ch: LocalChannel, in_ch: LocalChannel, bounds: TxBounds) -> list[dict] | RouteError:
+        exclude = [
+            # ensure the payment doesn't cross either channel in reverse.
+            # note that this doesn't preclude it from taking additional trips through self, with other peers.
+            # out_ch.directed_scid_to_me,
+            # in_ch.directed_scid_from_me,
+
+            # alternatively, never route through self. this avoids a class of logic error, like what to do with fees i charge "myself".
+            self.rpc.self_id
+        ] + self.bad_channels + self.nonzero_base_channels
+
+        out_peer = out_ch.remote_peer
+        in_peer = in_ch.remote_peer
+
+        route_or_bounds = bounds
+        while isinstance(route_or_bounds, TxBounds):
+            old_bounds = route_or_bounds
+            route_or_bounds = self._find_partial_route(out_peer, in_peer, old_bounds, exclude=exclude)
+            if route_or_bounds == old_bounds:
+                return RouteError.NO_ROUTE
+
+        if isinstance(route_or_bounds, RouteError):
+            return route_or_bounds
+
+        route = self._add_route_endpoints(route_or_bounds, out_ch, in_ch)
+        return route
+
+    def _find_partial_route(self, out_peer: str, in_peer: str, bounds: TxBounds, exclude: list[str]=[]) -> list[dict] | RouteError | TxBounds:
+        route = self.rpc.try_getroute(in_peer, amount_msat=bounds.max_msat, riskfactor=0, fromid=out_peer, exclude=exclude, cltv=CLTV)
+        if route is None:
+            logger.debug(f"no route for {bounds.max_msat}msat {out_peer} -> {in_peer}")
+            return RouteError.NO_ROUTE
+
+        send_msat = route[0]["amount_msat"]
+        if send_msat != Millisatoshi(bounds.max_msat):
+            logger.debug(f"found route with non-zero fee: {send_msat} -> {bounds.max_msat}. {route}")
+
+            error = None
+            for hop in route:
+                hop_scid = hop["channel"]
+                hop_dir = hop["direction"]
+                directed_scid = f"{hop_scid}/{hop_dir}"
+                ch = self._get_directed_scid(hop_scid, hop_dir)
+                if ch["base_fee_millisatoshi"] != 0:
+                    self.nonzero_base_channels.append(directed_scid)
+                    error = RouteError.HAS_BASE_FEE
+                bounds = bounds.restrict_to_zero_fees(ppm=ch["fee_per_millionth"], why=directed_scid)
+
+            return bounds.raise_max_to_be_satisfiable() if error is None else error
+
+        return route
+
+    def _add_route_endpoints(self, route, out_ch: LocalChannel, in_ch: LocalChannel):
+        inbound_hop = dict(
+          id=self.rpc.self_id,
+          channel=in_ch.scid,
+          direction=in_ch.direction_to_me,
+          amount_msat=route[-1]["amount_msat"],
+          delay=route[-1]["delay"],
+          style="tlv",
+        )
+        route = self._add_route_delay(route, in_ch.delay_them) + [ inbound_hop ]
+
+        outbound_hop = dict(
+            id=out_ch.remote_peer,
+            channel=out_ch.scid,
+            direction=out_ch.direction_from_me,
+            amount_msat=route[0]["amount_msat"],
+            delay=route[0]["delay"] + out_ch.delay_them,
+            style="tlv",
+        )
+        route = [ outbound_hop ] + route
+        return route
+
+    def _add_route_delay(self, route: list[dict], delay: int) -> list[dict]:
+        return [ dict(hop, delay=hop["delay"] + delay) for hop in route ]
+
+@dataclass
+class LoopJob:
+    out: str  # scid
+    in_: str  # scid
+    amount: int
+
+@dataclass
+class LoopJobIdle:
+    sec: int = 10
+
+class LoopJobDone(Enum):
+    COMPLETED = "COMPLETED"
+    ABORTED = "ABORTED"
+
+class AbstractLoopRunner:
+    def __init__(self, looper: LoopRouter, bounds: TxBounds, parallelism: int):
+        self.looper = looper
+        self.bounds = bounds
+        self.parallelism = parallelism
+        self.bounds_map = {}  # map (out:str, in_:str) -> TxBounds. it's a cache so we don't have to try 10 routes every time.
+
+    def pop_job(self) -> LoopJob | LoopJobIdle | LoopJobDone:
+        raise NotImplemented  # abstract method
+
+    def finished_job(self, job: LoopJob, progress: int|LoopError) -> None:
+        raise NotImplemented  # abstract method
+
+    def run_to_completion(self, exit_on_any_completed:bool = False) -> None:
+        self.exiting = False
+        self.exit_on_any_completed = exit_on_any_completed
+        if self.parallelism == 1:
+            # run inline to aid debugging
+            self._worker_thread()
+        else:
+            with ThreadPoolExecutor(max_workers=self.parallelism) as executor:
+                _ = list(executor.map(lambda _i: self._try_invoke(self._worker_thread), range(self.parallelism)))
+
+    def drop_caches(self) -> None:
+        logger.info("AbstractLoopRunner.drop_caches()")
+        self.looper.drop_caches()
+        self.bounds_map = {}
+
+
+    def _try_invoke(self, f, *args) -> None:
+        """
+        try to invoke `f` with the provided `args`, and log if it fails.
+        this overcomes the issue that background tasks which fail via Exception otherwise do so silently.
+        """
+        try:
+            f(*args)
+        except Exception as e:
+            logger.error(f"task failed: {e}")
+
+
+    def _worker_thread(self) -> None:
+        while not self.exiting:
+            job = self.pop_job()
+            logger.debug(f"popped job: {job}")
+            if isinstance(job, LoopJobDone):
+                return self._worker_finished(job)
+
+            if isinstance(job, LoopJobIdle):
+                logger.debug(f"idling for {job.sec}")
+                time.sleep(job.sec)
+                continue
+
+            result = self._execute_job(job)
+            logger.debug(f"finishing job {job} with {result}")
+            self.finished_job(job, result)
+
+    def _execute_job(self, job: LoopJob) -> LoopError|int:
+        bounds = self.bounds_map.get((job.out, job.in_), self.bounds)
+        bounds = bounds.intersect(TxBounds(max_msat=job.amount))
+        if not bounds.is_satisfiable():
+            logger.debug(f"TxBounds for job are unsatisfiable; skipping: {bounds} {job}")
+            return LoopError.NO_ROUTE
+
+        amt_looped = self.looper.loop_once(job.out, job.in_, bounds)
+        if amt_looped in (0, LoopError.NO_ROUTE, LoopError.TRANSIENT):
+            return amt_looped
+
+        logger.info(f"looped {amt_looped} from {job.out} -> {job.in_}")
+        bounds = bounds.intersect(TxBounds(max_msat=amt_looped))
+
+        self.bounds_map[(job.out, job.in_)] = bounds
+        return amt_looped
+
+    def _worker_finished(self, job: LoopJobDone) -> None:
+        if job == LoopJobDone.COMPLETED and self.exit_on_any_completed:
+            logger.debug(f"worker completed -> exiting pool")
+            self.exiting = True
+
+class LoopPairState:
+    # TODO: use this in MultiLoopBalancer, or stop shoving state in here and put it on LoopBalancer instead.
+    def __init__(self, out: str, in_: str, amount: int):
+        self.out = out
+        self.in_ = in_
+        self.amount_target = amount
+        self.amount_looped = 0
+        self.amount_outstanding = 0
+        self.tx_fail_count = 0
+        self.route_fail_count = 0
+        self.last_job_start_time = None
+        self.failed_tx_throttler = 0  # increase by one every time we fail, decreases more gradually, when we succeed
+
+class LoopBalancer(AbstractLoopRunner):
+    def __init__(self, out: str, in_: str, amount: int, looper: LoopRouter, bounds: TxBounds, parallelism: int=1):
+        super().__init__(looper, bounds, parallelism)
+        self.state = LoopPairState(out, in_, amount)
+
+    def pop_job(self) -> LoopJob | LoopJobIdle | LoopJobDone:
+        if self.state.tx_fail_count + 10*self.state.route_fail_count >= MAX_SEQUENTIAL_JOB_FAILURES:
+            logger.info(f"giving up ({self.state.out} -> {self.state.in_}): {self.state.tx_fail_count} tx failures, {self.state.route_fail_count} route failures")
+            return LoopJobDone.ABORTED
+
+        if self.state.tx_fail_count + self.state.route_fail_count > 0:
+            # N.B.: last_job_start_time is guaranteed to have been set by now
+            idle_until = self.state.last_job_start_time + TX_FAIL_BACKOFF*self.state.failed_tx_throttler
+            idle_for = idle_until - time.time()
+            if self.state.amount_outstanding != 0 or idle_for > 0:
+                # when we hit transient failures, restrict to just one job in flight at a time.
+                # this is aimed for the initial route building, where multiple jobs in flight is just useless,
+                # but it's not a bad idea for network blips, etc, either.
+                logger.info(f"throttling ({self.state.out} -> {self.state.in_}) for {idle_for:.0f}: {self.state.tx_fail_count} tx failures, {self.state.route_fail_count} route failures")
+                return LoopJobIdle(idle_for) if idle_for > 0 else LoopJobIdle()
+
+        amount_avail = self.state.amount_target - self.state.amount_looped - self.state.amount_outstanding
+        if amount_avail < self.bounds.min_msat:
+            if self.state.amount_outstanding == 0: return LoopJobDone.COMPLETED
+            return LoopJobIdle()  # sending out another job would risk over-transferring
+        amount_this_job = min(amount_avail, self.bounds.max_msat)
+
+        self.state.amount_outstanding += amount_this_job
+        self.state.last_job_start_time = time.time()
+        return LoopJob(out=self.state.out, in_=self.state.in_, amount=amount_this_job)
+
+    def finished_job(self, job: LoopJob, progress: int) -> None:
+        self.state.amount_outstanding -= job.amount
+        if progress == LoopError.NO_ROUTE:
+            self.state.route_fail_count += 1
+            self.state.failed_tx_throttler += 10
+        elif progress == LoopError.TRANSIENT:
+            self.state.tx_fail_count += 1
+            self.state.failed_tx_throttler += 1
+        else:
+            self.state.amount_looped += progress
+            self.state.tx_fail_count = 0
+            self.state.route_fail_count = 0
+            self.state.failed_tx_throttler = max(0, self.state.failed_tx_throttler - 0.2)
+        logger.info(f"loop progressed ({job.out} -> {job.in_}) {progress}: {self.state.amount_looped} of {self.state.amount_target}")
+
+class MultiLoopBalancer(AbstractLoopRunner):
+    """
+    multiplexes jobs between multiple LoopBalancers.
+    note that the child LoopBalancers don't actually execute the jobs -- just produce them.
+    """
+    def __init__(self, looper: LoopRouter, bounds: TxBounds, parallelism: int=1):
+        super().__init__(looper, bounds, parallelism)
+        self.loops = []
+        # job_index: increments on every job so we can grab jobs evenly from each LoopBalancer.
+        # in that event that producers are idling, it can actually increment more than once,
+        # so don't take this too literally
+        self.job_index = 0
+
+    def add_loop(self, out: LocalChannel, in_: LocalChannel, amount: int) -> None:
+        """
+        start looping sats from out -> in_
+        """
+        assert not any(l.state.out == out.scid and l.state.in_ == in_.scid for l in self.loops), f"tried to add duplicate loops from {out} -> {in_}"
+        logger.info(f"looping from ({out}) to ({in_})")
+        self.loops.append(LoopBalancer(out.scid, in_.scid, amount, self.looper, self.bounds, self.parallelism))
+
+    def pop_job(self) -> LoopJob | LoopJobIdle | LoopJobDone:
+        # N.B.: this can be called in parallel, so try to be consistent enough to not crash
+
+        idle_job = None
+        abort_job = None
+        for i, _ in enumerate(self.loops):
+            loop = self.loops[(self.job_index + i) % len(self.loops)]
+            self.job_index += 1
+            job = loop.pop_job()
+            if isinstance(job, LoopJob):
+                return job
+            if isinstance(job, LoopJobIdle):
+                idle_job = LoopJobIdle(min(job.sec, idle_job.sec)) if idle_job is not None else job
+            if job == LoopJobDone.ABORTED:
+                abort_job = job
+
+        # either there's a task to idle, or we have to terminate.
+        # if terminating, terminate ABORTED if any job aborted, else COMPLETED
+        if idle_job is not None: return idle_job
+        if abort_job is not None: return abort_job
+        return LoopJobDone.COMPLETED
+
+    def finished_job(self, job: LoopJob, progress: int) -> None:
+        # this assumes (enforced externally) that we have only one loop for a given out/in_ pair
+        for l in self.loops:
+            if l.state.out == job.out and l.state.in_ == job.in_:
+                l.finished_job(job, progress)
+
+        logger.info(f"total: {self.looper.metrics}")
+
+
+def balance_loop(rpc: RpcHelper, out: str, in_: str, amount_msat: int, min_msat: int, max_msat: int, parallelism: int):
+    looper = LoopRouter(rpc)
+    bounds = TxBounds(min_msat=min_msat, max_msat=max_msat)
+    balancer = LoopBalancer(out, in_, amount_msat, looper, bounds, parallelism)
+
+    balancer.run_to_completion()
+
+def autobalance_once(rpc: RpcHelper, metrics: Metrics, bounds: TxBounds, parallelism: int) -> bool:
+    """
+    autobalances all channels.
+    returns True if channels are balanced (or as balanced as can be); False if in need of further balancing
+    """
+    looper = LoopRouter(rpc, metrics)
+    balancer = MultiLoopBalancer(looper, bounds, parallelism)
+
+    channels = []
+    for peerch in rpc.rpc.listpeerchannels()["channels"]:
+        try:
+            channels.append(rpc.localchannel(peerch["short_channel_id"]))
+        except:
+            logger.info(f"NO CHANNELS for {peerch['peer_id']}")
+
+    channels = [ch for ch in channels if ch.online and ch.base_fee_to_me == 0]
+    give_to = [ ch for ch in channels if ch.send_ratio > 0.95 ]
+    take_from = [ ch for ch in channels if ch.send_ratio < 0.20 ]
+
+    if give_to == [] and take_from == []:
+        return True
+
+    for to in give_to:
+        for from_ in take_from:
+            balancer.add_loop(to, from_, 10000000)
+
+    balancer.run_to_completion(exit_on_any_completed=True)
+    return False
+
+
+def autobalance(rpc: RpcHelper, min_msat: int, max_msat: int, parallelism: int):
+    bounds = TxBounds(min_msat=min_msat, max_msat=max_msat)
+    metrics = Metrics()
+    while not autobalance_once(rpc, metrics, bounds, parallelism):
+        pass
+
+def show_status(rpc: RpcHelper, full: bool=False):
+    """
+    show a table of channel balances between peers.
+    """
+    for peerch in rpc.rpc.listpeerchannels()["channels"]:
+        try:
+            ch = rpc.localchannel(peerch["short_channel_id"])
+        except:
+            print(f"{peerch['peer_id']} scid:{peerch['short_channel_id']} state:{peerch['state']} NO CHANNELS")
+        else:
+            print(ch.to_str(with_scid=True, with_bal_ratio=True, with_payments=True, with_cost=full, with_ppm_theirs=True, with_ppm_mine=True, with_peer_id=full))
+
+def main():
+    logging.basicConfig()
+    logger.setLevel(logging.INFO)
+
+    parser = argparse.ArgumentParser(description="rebalance lightning channel balances")
+    parser.add_argument("--verbose", action="store_true", help="more logging")
+    parser.add_argument("--min-msat", default="999", help="min transaction size")
+    parser.add_argument("--max-msat", default="1000000", help="max transaction size")
+    parser.add_argument("--jobs", default="1", help="how many HTLCs to keep in-flight at once")
+    subparsers = parser.add_subparsers(help="action")
+
+    status_parser = subparsers.add_parser("status")
+    status_parser.set_defaults(action="status")
+    status_parser.add_argument("--full", action="store_true", help="more info per channel")
+
+    loop_parser = subparsers.add_parser("loop")
+    loop_parser.set_defaults(action="loop")
+    loop_parser.add_argument("out", help="peer id to send tx through")
+    loop_parser.add_argument("in_", help="peer id to receive tx through")
+    loop_parser.add_argument("amount", help="total amount of msat to loop")
+
+    autobal_parser = subparsers.add_parser("autobalance")
+    autobal_parser.set_defaults(action="autobalance")
+
+    args = parser.parse_args()
+
+    if args.verbose:
+        logger.setLevel(logging.DEBUG)
+
+    rpc = RpcHelper(LightningRpc(RPC_FILE))
+
+    if args.action == "status":
+        show_status(rpc, full=args.full)
+
+    if args.action == "loop":
+        balance_loop(rpc, out=args.out, in_=args.in_, amount_msat=int(args.amount), min_msat=int(args.min_msat), max_msat=int(args.max_msat), parallelism=int(args.jobs))
+
+    if args.action == "autobalance":
+        autobalance(rpc, min_msat=int(args.min_msat), max_msat=int(args.max_msat), parallelism=int(args.jobs))
+
+if __name__ == '__main__':
+    main()
--- a/hosts/by-name/servo/services/cryptocurrencies/clightning.nix
+++ b/hosts/by-name/servo/services/cryptocurrencies/clightning.nix
@@ -0,0 +1,135 @@
+# clightning is an implementation of Bitcoin's Lightning Network.
+# as such, this assumes that `services.bitcoin` is enabled.
+# docs:
+# - tor clightning config: <https://docs.corelightning.org/docs/tor>
+# - `lightning-cli` and subcommands: <https://docs.corelightning.org/reference/lightning-cli>
+# - `man lightningd-config`
+#
+# management/setup/use:
+# - guide: <https://github.com/ElementsProject/lightning>
+#
+# debugging:
+# - `lightning-cli getlog debug`
+# - `lightning-cli listpays`  -> show payments this node sent
+# - `lightning-cli listinvoices`  -> show payments this node received
+#
+# first, acquire peers:
+# - `lightning-cli connect id@host`
+#   where `id` is the node's pubkey, and `host` is perhaps an ip:port tuple, or a hash.onion:port tuple.
+#   for testing, choose any node listed on <https://1ml.com>
+# - `lightning-cli listpeers`
+#   should show the new peer, with `connected: true`
+#
+# then, fund the clightning wallet
+# - `lightning-cli newaddr`
+#
+# then, open channels
+# - `lightning-cli connect ...`
+# - `lightning-cli fundchannel <node_id> <amount_in_satoshis>`
+#
+# who to federate with?
+# - a lot of the larger nodes allow hands-free channel creation
+#   - either inbound or outbound, sometimes paid
+# - find nodes on:
+#   - <https://terminal.lightning.engineering/>
+#   - <https://1ml.com>
+#     - tor nodes: <https://1ml.com/node?order=capacity&iponionservice=true>
+#   - <https://lightningnetwork.plus>
+#   - <https://mempool.space/lightning>
+#   - <https://amboss.space>
+# - a few tor-capable nodes which allow channel creation:
+#   - <https://c-otto.de/>
+#   - <https://cyberdyne.sh/>
+#   - <https://yalls.org/about/>
+#   - <https://coincept.com/>
+# - more resources: <https://www.lopp.net/lightning-information.html>
+#   - node routability: https://hashxp.org/lightning/node/<id>
+# - especially, acquire inbound liquidity via lightningnetwork.plus's swap feature
+#   - most of the opportunities are gated behind a minimum connection or capacity requirement
+#
+# tune payment parameters
+# - `lightning-cli setchannel <id> [feebase] [feeppm] [htlcmin] [htlcmax] [enforcedelay] [ignorefeelimits]`
+#   - e.g. `lightning-cli setchannel all 0 10`
+#   - it's suggested that feebase=0 simplifies routing.
+#
+# teardown:
+# - `lightning-cli withdraw <bc1... dest addr> <amount in satoshis> [feerate]`
+#
+# sanity:
+# - `lightning-cli listfunds`
+#
+# to receive a payment (do as `clightning` user):
+# - `lightning-cli invoice <amount in millisatoshi> <label> <description>`
+#   - specify amount as `any` if undetermined
+#   - then give the resulting bolt11 URI to the payer
+# to send a payment:
+# - `lightning-cli pay <bolt11 URI>`
+#   - or `lightning-cli pay <bolt11 URI> [amount_msat] [label] [riskfactor] [maxfeepercent] ...`
+#   - amount_msat must be "null" if the bolt11 URI specifies a value
+#   - riskfactor defaults to 10
+#   - maxfeepercent defaults to 0.5
+#   - label is a human-friendly label for my records
+
+{ config, pkgs, ... }:
+{
+  sane.persist.sys.byStore.ext = [
+    { user = "clightning"; group = "clightning"; mode = "0710"; path = "/var/lib/clightning"; method = "bind"; }
+  ];
+
+  # `lightning-cli` finds its RPC file via `~/.lightning/bitcoin/lightning-rpc`, to message the daemon
+  sane.user.fs.".lightning".symlink.target = "/var/lib/clightning";
+
+  # see bitcoin.nix for how to generate this
+  services.bitcoind.mainnet.rpc.users.clightning.passwordHMAC =
+    "befcb82d9821049164db5217beb85439$2c31ac7db3124612e43893ae13b9527dbe464ab2d992e814602e7cb07dc28985";
+
+  sane.services.clightning.enable = true;
+  sane.services.clightning.proxy = "127.0.0.1:9050";  # proxy outgoing traffic through tor
+  # sane.services.clightning.publicAddress = "statictor:127.0.0.1:9051";
+  sane.services.clightning.getPublicAddressCmd = "cat /var/lib/tor/onion/clightning/hostname";
+
+  services.tor.relay.onionServices.clightning = {
+    version = 3;
+    map = [{
+      # by default tor will route public tor port P to 127.0.0.1:P.
+      # so if this port is the same as clightning would natively use, then no further config is needed here.
+      # see: <https://2019.www.torproject.org/docs/tor-manual.html.en#HiddenServicePort>
+      port = 9735;
+      # target.port; target.addr;  #< set if tor port != clightning port
+    }];
+    # allow "tor" group (i.e. clightning) to read /var/lib/tor/onion/clightning/hostname
+    settings.HiddenServiceDirGroupReadable = true;
+  };
+
+  # must be in "tor" group to read /var/lib/tor/onion/*/hostname
+  users.users.clightning.extraGroups = [ "tor" ];
+
+  systemd.services.clightning.after = [ "tor.service" ];
+
+  # lightning-config contains fields from here:
+  # - <https://docs.corelightning.org/docs/configuration>
+  # secret config includes:
+  # - bitcoin-rpcpassword
+  # - alias=nodename
+  # - rgb=rrggbb
+  # - fee-base=<millisatoshi>
+  # - fee-per-satoshi=<ppm>
+  # - feature configs (i.e. experimental-xyz options)
+  sane.services.clightning.extraConfig = ''
+    log-level=debug:lightningd
+    # peerswap:
+    # - config example: <https://github.com/fort-nix/nix-bitcoin/pull/462/files#diff-b357d832705b8ce8df1f41934d613f79adb77c4cd5cd9e9eb12a163fca3e16c6>
+    # XXX: peerswap crashes clightning on launch. stacktrace is useless.
+    # plugin=${pkgs.peerswap}/bin/peerswap
+    # peerswap-db-path=/var/lib/clightning/peerswap/swaps
+    # peerswap-policy-path=...
+  '';
+  sane.services.clightning.extraConfigFiles = [ config.sops.secrets."lightning-config".path ];
+  sops.secrets."lightning-config" = {
+    mode = "0640";
+    owner = "clightning";
+    group = "clightning";
+  };
+
+  sane.programs.clightning.enableFor.user.colin = true;  # for debugging/admin: `lightning-cli`
+}
--- a/hosts/by-name/servo/services/cryptocurrencies/default.nix
+++ b/hosts/by-name/servo/services/cryptocurrencies/default.nix
@@ -0,0 +1,10 @@
+{ ... }:
+{
+  imports = [
+    ./bitcoin.nix
+    ./clightning.nix
+    ./i2p.nix
+    ./monero.nix
+    ./tor.nix
+  ];
+}
--- a/hosts/by-name/servo/services/cryptocurrencies/i2p.nix
+++ b/hosts/by-name/servo/services/cryptocurrencies/i2p.nix
@@ -0,0 +1,4 @@
+{ ... }:
+{
+  services.i2p.enable = true;
+}
--- a/hosts/by-name/servo/services/cryptocurrencies/monero.nix
+++ b/hosts/by-name/servo/services/cryptocurrencies/monero.nix
@@ -0,0 +1,31 @@
+# as of 2023/11/26: complete downloaded blockchain should be 200GiB on disk, give or take.
+{ ... }:
+{
+  sane.persist.sys.byStore.ext = [
+    # /var/lib/monero/lmdb is what consumes most of the space
+    { user = "monero"; group = "monero"; path = "/var/lib/monero"; method = "bind"; }
+  ];
+
+  services.monero.enable = true;
+  services.monero.limits.upload = 5000;  # in kB/s
+  services.monero.extraConfig = ''
+    # see: monero doc/ANONYMITY_NETWORKS.md
+    #
+    # "If any anonymity network is enabled, transactions being broadcast that lack a valid 'context'
+    # (i.e. the transaction did not come from a P2P connection) will only be sent to peers on anonymity networks."
+    #
+    # i think this means that setting tx-proxy here ensures any transactions sent locally to my node (via RPC)
+    # will be sent over an anonymity network.
+    tx-proxy=i2p,127.0.0.1:9000
+    tx-proxy=tor,127.0.0.1:9050
+  '';
+
+  # monero ports: <https://monero.stackexchange.com/questions/604/what-ports-does-monero-use-rpc-p2p-etc>
+  # - 18080 = "P2P" monero node <-> monero node connections
+  # - 18081 = "RPC" monero client -> monero node connections
+  sane.ports.ports."18080" = {
+    protocol = [ "tcp" ];
+    visibleTo.wan = true;
+    description = "colin-monero-p2p";
+  };
+}
--- a/hosts/by-name/servo/services/cryptocurrencies/tor.nix
+++ b/hosts/by-name/servo/services/cryptocurrencies/tor.nix
@@ -0,0 +1,25 @@
+# tor settings: <https://2019.www.torproject.org/docs/tor-manual.html.en>
+{ lib, ... }:
+{
+  # tor hidden service hostnames aren't deterministic, so persist.
+  # might be able to get away with just persisting /var/lib/tor/onion, not sure.
+  sane.persist.sys.byStore.plaintext = [
+    { user = "tor"; group = "tor"; mode = "0710"; path = "/var/lib/tor"; method = "bind"; }
+  ];
+
+  # tor: `tor.enable` doesn't start a relay, exit node, proxy, etc. it's minimal.
+  # tor.client.enable configures a torsocks proxy, accessible *only* to localhost.
+  #   at 127.0.0.1:9050
+  services.tor.enable = true;
+  services.tor.client.enable = true;
+
+  # in order for services to read /var/lib/tor/onion/*/hostname, they must be able to traverse /var/lib/tor,
+  # and /var/lib/tor must have g+x.
+  # DataDirectoryGroupReadable causes tor to use g+rx, technically more than we need, but all the files are 600 so it's fine.
+  services.tor.settings.DataDirectoryGroupReadable = true;
+  # StateDirectoryMode defaults to 0700, and thereby prevents the onion hostnames from being group readable
+  systemd.services.tor.serviceConfig.StateDirectoryMode = lib.mkForce "0710";
+  users.users.tor.homeMode = "0710";  # home mode defaults to 0700, causing readability problems, enforced by nixos "users" activation script
+
+  services.tor.settings.SafeLogging = false;  # show actual .onion names in the syslog, else debugging is impossible
+}
--- a/hosts/by-name/servo/services/ddns-afraid.nix
+++ b/hosts/by-name/servo/services/ddns-afraid.nix
@@ -1,27 +0,0 @@
-{ config, lib, pkgs, ... }:
-
-# using manual ddns now
-lib.mkIf false
-{
-  systemd.services.ddns-afraid = {
-    description = "update dynamic DNS entries for freedns.afraid.org";
-    serviceConfig = {
-      EnvironmentFile = config.sops.secrets."ddns_afraid.env".path;
-      # TODO: ProtectSystem = "strict";
-      # TODO: ProtectHome = "full";
-      # TODO: PrivateTmp = true;
-    };
-    script = let
-      curl = "${pkgs.curl}/bin/curl -4";
-    in ''
-      ${curl} "https://freedns.afraid.org/dynamic/update.php?$AFRAID_KEY"
-    '';
-  };
-  systemd.timers.ddns-afraid = {
-    wantedBy = [ "multi-user.target" ];
-    timerConfig = {
-      OnStartupSec = "2min";
-      OnUnitActiveSec = "10min";
-    };
-  };
-}
--- a/hosts/by-name/servo/services/ddns-he.nix
+++ b/hosts/by-name/servo/services/ddns-he.nix
@@ -1,30 +0,0 @@
-{ config, lib, pkgs, ... }:
-
-# we use manual DDNS now
-lib.mkIf false
-{
-  systemd.services.ddns-he = {
-    description = "update dynamic DNS entries for HurricaneElectric";
-    serviceConfig = {
-      EnvironmentFile = config.sops.secrets."ddns_he.env".path;
-      # TODO: ProtectSystem = "strict";
-      # TODO: ProtectHome = "full";
-      # TODO: PrivateTmp = true;
-    };
-    # HE DDNS API is documented: https://dns.he.net/docs.html
-    script = let
-      crl = "${pkgs.curl}/bin/curl -4";
-    in ''
-      ${crl} "https://he.uninsane.org:$HE_PASSPHRASE@dyn.dns.he.net/nic/update?hostname=he.uninsane.org"
-      ${crl} "https://native.uninsane.org:$HE_PASSPHRASE@dyn.dns.he.net/nic/update?hostname=native.uninsane.org"
-      ${crl} "https://uninsane.org:$HE_PASSPHRASE@dyn.dns.he.net/nic/update?hostname=uninsane.org"
-    '';
-  };
-  systemd.timers.ddns-he = {
-    wantedBy = [ "multi-user.target" ];
-    timerConfig = {
-      OnStartupSec = "2min";
-      OnUnitActiveSec = "10min";
-    };
-  };
-}
--- a/hosts/by-name/servo/services/default.nix
+++ b/hosts/by-name/servo/services/default.nix
@@ -3,8 +3,7 @@
  imports = [
    ./calibre.nix
    ./coturn.nix
-    ./ddns-afraid.nix
-    ./ddns-he.nix
+    ./cryptocurrencies
    ./email
    ./ejabberd.nix
    ./freshrss.nix
@@ -20,12 +19,14 @@
    ./matrix
    ./navidrome.nix
    ./nginx.nix
+    ./nixos-prebuild.nix
    ./nixserve.nix
    ./ntfy
    ./pict-rs.nix
    ./pleroma.nix
    ./postgres.nix
    ./prosody
+    ./slskd.nix
    ./transmission.nix
    ./trust-dns.nix
    ./wikipedia.nix
--- a/hosts/by-name/servo/services/ejabberd.nix
+++ b/hosts/by-name/servo/services/ejabberd.nix
@@ -45,7 +45,7 @@ in
 lib.mkIf false
 {
  sane.persist.sys.byStore.plaintext = [
-    { user = "ejabberd"; group = "ejabberd"; path = "/var/lib/ejabberd"; }
+    { user = "ejabberd"; group = "ejabberd"; path = "/var/lib/ejabberd"; method = "bind"; }
  ];
  sane.ports.ports = lib.mkMerge ([
    {
--- a/hosts/by-name/servo/services/email/dovecot.nix
+++ b/hosts/by-name/servo/services/email/dovecot.nix
@@ -127,10 +127,11 @@
  services.dovecot2.modules = [
    pkgs.dovecot_pigeonhole  # enables sieve execution (?)
  ];
-  services.dovecot2.sieveScripts = {
+  services.dovecot2.sieve = {
+    extensions = [ "fileinto" ];
    # if any messages fail to pass (or lack) DKIM, move them to Junk
    # XXX the key name ("after") is only used to order sieve execution/ordering
-    after = builtins.toFile "ensuredkim.sieve" ''
+    scripts.after = builtins.toFile "ensuredkim.sieve" ''
      require "fileinto";

      if not header :contains "Authentication-Results" "dkim=pass" {
@@ -139,4 +140,6 @@
      }
    '';
  };
+
+  systemd.services.dovecot2.serviceConfig.RestartSec = lib.mkForce "15s";  # nixos defaults this to 1s
 }
--- a/hosts/by-name/servo/services/email/postfix.nix
+++ b/hosts/by-name/servo/services/email/postfix.nix
@@ -20,9 +20,9 @@ in
 {
  sane.persist.sys.byStore.plaintext = [
    # TODO: mode? could be more granular
-    { user = "opendkim"; group = "opendkim"; path = "/var/lib/opendkim"; }
-    { user = "root"; group = "root"; path = "/var/lib/postfix"; }
-    { user = "root"; group = "root"; path = "/var/spool/mail"; }
+    { user = "opendkim"; group = "opendkim"; path = "/var/lib/opendkim"; method = "bind"; }
+    { user = "root"; group = "root"; path = "/var/lib/postfix"; method = "bind"; }
+    { user = "root"; group = "root"; path = "/var/spool/mail"; method = "bind"; }
    # *probably* don't need these dirs:
    # "/var/lib/dhparams"          # https://github.com/NixOS/nixpkgs/blob/master/nixos/modules/security/dhparams.nix
    # "/var/lib/dovecot"
--- a/hosts/by-name/servo/services/export/default.nix
+++ b/hosts/by-name/servo/services/export/default.nix
@@ -29,8 +29,8 @@
  # - `sudo btrfs qgroup limit 20G /mnt/persist/ext/persist/var/export/playground`
  # to query the quota/status:
  # - `sudo btrfs qgroup show -re /var/export/playground`
-  sane.persist.sys.ext = [
-    { user = "root"; group = "export"; mode = "0775"; path = "/var/export/playground"; }
+  sane.persist.sys.byStore.ext = [
+    { user = "root"; group = "export"; mode = "0775"; path = "/var/export/playground"; method = "bind"; }
  ];

  sane.fs."/var/export/README.md" = {
--- a/hosts/by-name/servo/services/export/sftpgo.nix
+++ b/hosts/by-name/servo/services/export/sftpgo.nix
@@ -91,7 +91,7 @@ let
  authFailJson = pkgs.writeText "sftp-auth-fail.json" (builtins.toJSON authResponseFail);
  unwrappedAuthProgram = pkgs.static-nix-shell.mkBash {
    pname = "sftpgo_external_auth_hook";
-    src = ./.;
+    srcRoot = ./.;
    pkgs = [ "coreutils" ];
  };
  authProgram = pkgs.writeShellScript "sftpgo-auth-hook" ''
@@ -172,13 +172,15 @@ in

  users.users.sftpgo.extraGroups = [ "export" ];

-  systemd.services.sftpgo.serviceConfig = {
-    ReadOnlyPaths = [ "/var/export" ];
-    ReadWritePaths = [ "/var/export/playground" ];
+  systemd.services.sftpgo = {
    after = [ "network-online.target" ];
    wants = [ "network-online.target" ];
+    serviceConfig = {
+      ReadOnlyPaths = [ "/var/export" ];
+      ReadWritePaths = [ "/var/export/playground" ];

      Restart = "always";
      RestartSec = "20s";
    };
+  };
 }
--- a/hosts/by-name/servo/services/freshrss.nix
+++ b/hosts/by-name/servo/services/freshrss.nix
@@ -16,7 +16,7 @@
    mode = "0400";
  };
  sane.persist.sys.byStore.plaintext = [
-    { user = "freshrss"; group = "freshrss"; path = "/var/lib/freshrss"; }
+    { user = "freshrss"; group = "freshrss"; path = "/var/lib/freshrss"; method = "bind"; }
  ];

  services.freshrss.enable = true;
--- a/hosts/by-name/servo/services/gitea.nix
+++ b/hosts/by-name/servo/services/gitea.nix
@@ -4,7 +4,7 @@
 {
  sane.persist.sys.byStore.plaintext = [
    # TODO: mode? could be more granular
-    { user = "git"; group = "gitea"; path = "/var/lib/gitea"; }
+    { user = "git"; group = "gitea"; path = "/var/lib/gitea"; method = "bind"; }
  ];
  services.gitea.enable = true;
  services.gitea.user = "git";  # default is 'gitea'
@@ -13,6 +13,10 @@
  services.gitea.appName = "Perfectly Sane Git";
  # services.gitea.disableRegistration = true;

+  services.gitea.database.createDatabase = false;  #< silence warning which wants db user and name to be equal
+  # TODO: remove this after merge: <https://github.com/NixOS/nixpkgs/pull/268849>
+  services.gitea.database.socket = "/run/postgresql";  #< would have been set if createDatabase = true
+
  # gitea doesn't create the git user
  users.users.git = {
    description = "Gitea Service";
@@ -96,6 +100,24 @@
    locations."/" = {
      proxyPass = "http://127.0.0.1:3000";
    };
+    # gitea serves all `raw` files as content-type: plain, but i'd like to serve them as their actual content type.
+    # or at least, enough to make specific pages viewable (serving unoriginal content as arbitrary content type is dangerous).
+    locations."~ ^/colin/phone-case-cq/raw/.*.html" = {
+      proxyPass = "http://127.0.0.1:3000";
+      extraConfig = ''
+        proxy_hide_header Content-Type;
+        default_type text/html;
+        add_header Content-Type text/html;
+      '';
+    };
+    locations."~ ^/colin/phone-case-cq/raw/.*.js" = {
+      proxyPass = "http://127.0.0.1:3000";
+      extraConfig = ''
+        proxy_hide_header Content-Type;
+        default_type text/html;
+        add_header Content-Type text/javascript;
+      '';
+    };
  };

  sane.dns.zones."uninsane.org".inet.CNAME."git" = "native";
--- a/hosts/by-name/servo/services/ipfs.nix
+++ b/hosts/by-name/servo/services/ipfs.nix
@@ -12,7 +12,7 @@ lib.mkIf false # i don't actively use ipfs anymore
 {
  sane.persist.sys.byStore.plaintext = [
    # TODO: mode? could be more granular
-    { user = "261"; group = "261"; path = "/var/lib/ipfs"; }
+    { user = "261"; group = "261"; path = "/var/lib/ipfs"; method = "bind"; }
  ];

  networking.firewall.allowedTCPPorts = [ 4001 ];
--- a/hosts/by-name/servo/services/jackett.nix
+++ b/hosts/by-name/servo/services/jackett.nix
@@ -3,7 +3,7 @@
 {
  sane.persist.sys.byStore.plaintext = [
    # TODO: mode? we only need this to save Indexer creds ==> migrate to config?
-    { user = "root"; group = "root"; path = "/var/lib/jackett"; }
+    { user = "root"; group = "root"; path = "/var/lib/jackett"; method = "bind"; }
  ];
  services.jackett.enable = true;

--- a/hosts/by-name/servo/services/jellyfin.nix
+++ b/hosts/by-name/servo/services/jellyfin.nix
@@ -41,7 +41,7 @@
  };

  sane.persist.sys.byStore.plaintext = [
-    { user = "jellyfin"; group = "jellyfin"; mode = "0700"; path = "/var/lib/jellyfin"; }
+    { user = "jellyfin"; group = "jellyfin"; mode = "0700"; path = "/var/lib/jellyfin"; method = "bind"; }
  ];
  sane.fs."/var/lib/jellyfin/config/logging.json" = {
    # "Emby.Dlna" logging: <https://jellyfin.org/docs/general/networking/dlna>
--- a/hosts/by-name/servo/services/kiwix-serve.nix
+++ b/hosts/by-name/servo/services/kiwix-serve.nix
@@ -1,9 +1,19 @@
+# how to update wikipedia snapshot:
+# - browse for later snapshots:
+#   - <https://mirror.accum.se/mirror/wikimedia.org/other/kiwix/zim/wikipedia>
+# - DL directly, or via rsync (resumable):
+#   - `rsync --progress --append-verify rsync://mirror.accum.se/mirror/wikimedia.org/other/kiwix/zim/wikipedia/wikipedia_en_all_maxi_2022-05.zim .`
+
 { ... }:
 {
+  sane.persist.sys.byStore.ext = [
+    { user = "colin"; group = "users"; path = "/var/lib/kiwix"; method = "bind"; }
+  ];
+
  sane.services.kiwix-serve = {
    enable = true;
    port = 8013;
-    zimPaths = [ "/var/lib/uninsane/www-archive/wikipedia_en_all_maxi_2022-05.zim" ];
+    zimPaths = [ "/var/lib/kiwix/wikipedia_en_all_maxi_2023-11.zim" ];
  };

  services.nginx.virtualHosts."w.uninsane.org" = {
--- a/hosts/by-name/servo/services/komga.nix
+++ b/hosts/by-name/servo/services/komga.nix
@@ -5,7 +5,7 @@ let
 in
 {
  sane.persist.sys.byStore.plaintext = [
-    { inherit user group; mode = "0700"; path = stateDir; }
+    { inherit user group; mode = "0700"; path = stateDir; method = "bind"; }
  ];

  services.komga.enable = true;
--- a/hosts/by-name/servo/services/lemmy.nix
+++ b/hosts/by-name/servo/services/lemmy.nix
@@ -78,8 +78,8 @@ in {
  # CLI args: <https://git.asonix.dog/asonix/pict-rs#user-content-running>
  systemd.services.pict-rs.serviceConfig.ExecStart = lib.mkForce (lib.concatStringsSep " " [
    "${lib.getBin pict-rs}/bin/pict-rs run"
-    "--media-max-frame-count" (builtins.toString (30*60*60))
+    "--media-video-max-frame-count" (builtins.toString (30*60*60))
    "--media-process-timeout 120"
-    "--media-enable-full-video true"  # allow audio
+    "--media-video-allow-audio"  # allow audio
  ]);
 }
--- a/hosts/by-name/servo/services/matrix/default.nix
+++ b/hosts/by-name/servo/services/matrix/default.nix
@@ -21,7 +21,7 @@
  ];

  sane.persist.sys.byStore.plaintext = [
-    { user = "matrix-synapse"; group = "matrix-synapse"; path = "/var/lib/matrix-synapse"; }
+    { user = "matrix-synapse"; group = "matrix-synapse"; path = "/var/lib/matrix-synapse"; method = "bind"; }
  ];
  services.matrix-synapse.enable = true;
  services.matrix-synapse.settings = {
--- a/hosts/by-name/servo/services/matrix/discord-puppet.nix
+++ b/hosts/by-name/servo/services/matrix/discord-puppet.nix
@@ -6,7 +6,7 @@
 lib.mkIf false
 {
  sane.persist.sys.byStore.plaintext = [
-    { user = "matrix-synapse"; group = "matrix-synapse"; path = "/var/lib/mx-puppet-discord"; }
+    { user = "matrix-synapse"; group = "matrix-synapse"; path = "/var/lib/mx-puppet-discord"; method = "bind"; }
  ];

  services.matrix-synapse.settings.app_service_config_files = [
--- a/hosts/by-name/servo/services/matrix/irc.nix
+++ b/hosts/by-name/servo/services/matrix/irc.nix
@@ -103,7 +103,7 @@ in

  sane.persist.sys.byStore.plaintext = [
    # TODO: mode?
-    { user = "matrix-appservice-irc"; group = "matrix-appservice-irc"; path = "/var/lib/matrix-appservice-irc"; }
+    { user = "matrix-appservice-irc"; group = "matrix-appservice-irc"; path = "/var/lib/matrix-appservice-irc"; method = "bind"; }
  ];

  # XXX: matrix-appservice-irc PreStart tries to chgrp the registration.yml to matrix-synapse,
--- a/hosts/by-name/servo/services/matrix/signal.nix
+++ b/hosts/by-name/servo/services/matrix/signal.nix
@@ -1,10 +1,12 @@
 # config options:
 # - <https://github.com/mautrix/signal/blob/master/mautrix_signal/example-config.yaml>
-{ config, pkgs, ... }:
+{ config, lib, pkgs, ... }:
+
+lib.mkIf false  # disabled 2024/01/11: i don't use it, and pkgs.mautrix-signal had some API changes
 {
  sane.persist.sys.byStore.plaintext = [
-    { user = "mautrix-signal"; group = "mautrix-signal"; path = "/var/lib/mautrix-signal"; }
-    { user = "signald"; group = "signald"; path = "/var/lib/signald"; }
+    { user = "mautrix-signal"; group = "mautrix-signal"; path = "/var/lib/mautrix-signal"; method = "bind"; }
+    { user = "signald"; group = "signald"; path = "/var/lib/signald"; method = "bind"; }
  ];

  # allow synapse to read the registration file
--- a/hosts/by-name/servo/services/navidrome.nix
+++ b/hosts/by-name/servo/services/navidrome.nix
@@ -2,7 +2,7 @@

 {
  sane.persist.sys.byStore.plaintext = [
-    { user = "navidrome"; group = "navidrome"; path = "/var/lib/navidrome"; }
+    { user = "navidrome"; group = "navidrome"; path = "/var/lib/navidrome"; method = "bind"; }
  ];
  services.navidrome.enable = true;
  services.navidrome.settings = {
--- a/hosts/by-name/servo/services/nginx.nix
+++ b/hosts/by-name/servo/services/nginx.nix
@@ -54,8 +54,10 @@ in
  services.nginx.recommendedOptimisation = true;

  # web blog/personal site
+  # alternative way to link stuff into the share:
+  # sane.fs."/var/lib/uninsane/share/Ubunchu".mount.bind = "/var/lib/uninsane/media/Books/Visual/HiroshiSeo/Ubunchu";
+  # sane.fs."/var/lib/uninsane/media/Books/Visual/HiroshiSeo/Ubunchu".dir = {};
  services.nginx.virtualHosts."uninsane.org" = publog {
-    root = "${pkgs.uninsane-dot-org}/share/uninsane-dot-org";
    # a lot of places hardcode https://uninsane.org,
    # and then when we mix http + non-https, we get CORS violations
    # and things don't look right. so force SSL.
@@ -65,9 +67,28 @@ in
    # for OCSP stapling
    sslTrustedCertificate = "${pkgs.cacert}/etc/ssl/certs/ca-bundle.crt";

-    # uninsane.org/share/foo => /var/lib/uninsane/root/share/foo.
-    # yes, nginx does not strip the prefix when evaluating against the root.
-    locations."/share".root = "/var/lib/uninsane/root";
+    locations."/" = {
+      root = "${pkgs.uninsane-dot-org}/share/uninsane-dot-org";
+      tryFiles = "$uri $uri/ @fallback";
+    };
+
+    # unversioned files
+    locations."@fallback" = {
+      root = "/var/www/sites/uninsane.org";
+    };
+
+    # uninsane.org/share/foo => /var/www/sites/uninsane.org/share/foo.
+    # special-cased to enable directory listings
+    locations."/share" = {
+      root = "/var/www/sites/uninsane.org";
+      extraConfig = ''
+        # autoindex => render directory listings
+        autoindex on;
+        # don't follow any symlinks when serving files
+        # otherwise it allows a directory escape
+        disable_symlinks on;
+      '';
+    };

    # allow matrix users to discover that @user:uninsane.org is reachable via matrix.uninsane.org
    locations."= /.well-known/matrix/server".extraConfig =
@@ -108,6 +129,19 @@ in
    #   proxyPass = "http://127.0.0.1:4000";
    #   extraConfig = pleromaExtraConfig;
    # };
+
+    # redirect common feed URIs to the canonical feed
+    locations."= /atom".extraConfig = "return 301 /atom.xml;";
+    locations."= /feed".extraConfig = "return 301 /atom.xml;";
+    locations."= /feed.xml".extraConfig = "return 301 /atom.xml;";
+    locations."= /rss".extraConfig = "return 301 /atom.xml;";
+    locations."= /rss.xml".extraConfig = "return 301 /atom.xml;";
+    locations."= /blog/atom".extraConfig = "return 301 /atom.xml;";
+    locations."= /blog/atom.xml".extraConfig = "return 301 /atom.xml;";
+    locations."= /blog/feed".extraConfig = "return 301 /atom.xml;";
+    locations."= /blog/feed.xml".extraConfig = "return 301 /atom.xml;";
+    locations."= /blog/rss".extraConfig = "return 301 /atom.xml;";
+    locations."= /blog/rss.xml".extraConfig = "return 301 /atom.xml;";
  };


@@ -135,9 +169,8 @@ in
  security.acme.defaults.email = "admin.acme@uninsane.org";

  sane.persist.sys.byStore.plaintext = [
-    # TODO: mode?
-    { user = "acme"; group = "acme"; path = "/var/lib/acme"; }
-    { user = "colin"; group = "users"; path = "/var/www/sites"; }
+    { user = "acme"; group = "acme"; path = "/var/lib/acme"; method = "bind"; }
+    { user = "colin"; group = "users"; path = "/var/www/sites"; method = "bind"; }
  ];

  # let's encrypt default chain looks like:
--- a/hosts/by-name/servo/services/nixos-prebuild.nix
+++ b/hosts/by-name/servo/services/nixos-prebuild.nix
@@ -0,0 +1,26 @@
+{ lib, pkgs, ... }:
+
+lib.optionalAttrs false  # disabled until i can be sure it's not gonna OOM my server in the middle of the night
+{
+  systemd.services.nixos-prebuild = {
+    description = "build a nixos image with all updated deps";
+    path = with pkgs; [ coreutils git nix ];
+    script = ''
+      working=$(mktemp -d /tmp/nixos-prebuild.XXXXXX)
+      pushd "$working"
+      git clone https://git.uninsane.org/colin/nix-files.git \
+        && cd nix-files \
+        && nix flake update \
+        || true
+      RC=$(nix run "$working/nix-files#check" -- -j1 --cores 5 --builders "")
+      popd
+      rm -rf "$working"
+      exit "$RC"
+    '';
+  };
+
+  systemd.timers.nixos-prebuild = {
+    wantedBy = [ "multi-user.target" ];
+    timerConfig.OnCalendar = "11,23:00:00";
+  };
+}
--- a/hosts/by-name/servo/services/ntfy/ntfy-sh.nix
+++ b/hosts/by-name/servo/services/ntfy/ntfy-sh.nix
@@ -34,7 +34,7 @@ in
    # not 100% necessary to persist this, but ntfy does keep a 12hr (by default) cache
    # for pushing notifications to users who become offline.
    # ACLs also live here.
-    { user = "ntfy-sh"; group ="ntfy-sh"; path = "/var/lib/ntfy-sh"; }
+    { user = "ntfy-sh"; group ="ntfy-sh"; path = "/var/lib/ntfy-sh"; method = "bind"; }
  ];

  services.ntfy-sh.enable = true;
--- a/hosts/by-name/servo/services/ntfy/ntfy-waiter.nix
+++ b/hosts/by-name/servo/services/ntfy/ntfy-waiter.nix
@@ -49,7 +49,7 @@ in
      type = types.package;
      default = pkgs.static-nix-shell.mkPython3Bin {
        pname = "ntfy-waiter";
-        src = ./.;
+        srcRoot = ./.;
        pkgs = [ "ntfy-sh" ];
      };
      description = ''
@@ -64,7 +64,7 @@ in
        protocol = [ "tcp" ];
        visibleTo.lan = true;
        visibleTo.wan = true;
-        description = "colin-notification-waiter-${builtins.toString (port+1)}-of-${builtins.toString numPorts}";
+        description = "colin-notification-waiter-${builtins.toString (port - portLow + 1)}-of-${builtins.toString numPorts}";
      };
    }));
    systemd.services = lib.mkMerge (builtins.map mkService portRange);
--- a/hosts/by-name/servo/services/pict-rs.nix
+++ b/hosts/by-name/servo/services/pict-rs.nix
@@ -6,7 +6,7 @@ let
 in
 {
  sane.persist.sys.byStore.plaintext = lib.mkIf cfg.enable [
-    { user = "pict-rs"; group = "pict-rs"; path = cfg.dataDir; }
+    { user = "pict-rs"; group = "pict-rs"; path = cfg.dataDir; method = "bind"; }
  ];

  systemd.services.pict-rs.serviceConfig = {
--- a/hosts/by-name/servo/services/pleroma.nix
+++ b/hosts/by-name/servo/services/pleroma.nix
@@ -15,7 +15,7 @@ let
 in
 {
  sane.persist.sys.byStore.plaintext = [
-    { user = "pleroma"; group = "pleroma"; path = "/var/lib/pleroma"; }
+    { user = "pleroma"; group = "pleroma"; path = "/var/lib/pleroma"; method = "bind"; }
  ];
  services.pleroma.enable = true;
  services.pleroma.secretConfigFile = config.sops.secrets.pleroma_secrets.path;
--- a/hosts/by-name/servo/services/postgres.nix
+++ b/hosts/by-name/servo/services/postgres.nix
@@ -8,7 +8,7 @@ in
 {
  sane.persist.sys.byStore.plaintext = [
    # TODO: mode?
-    { user = "postgres"; group = "postgres"; path = "/var/lib/postgresql"; }
+    { user = "postgres"; group = "postgres"; path = "/var/lib/postgresql"; method = "bind"; }
  ];
  services.postgresql.enable = true;

--- a/hosts/by-name/servo/services/prosody/default.nix
+++ b/hosts/by-name/servo/services/prosody/default.nix
@@ -57,7 +57,7 @@ let
 in
 {
  sane.persist.sys.byStore.plaintext = [
-    { user = "prosody"; group = "prosody"; path = "/var/lib/prosody"; }
+    { user = "prosody"; group = "prosody"; path = "/var/lib/prosody"; method = "bind"; }
  ];
  sane.ports.ports."5000" = {
    protocol = [ "tcp" ];
--- a/hosts/by-name/servo/services/slskd.nix
+++ b/hosts/by-name/servo/services/slskd.nix
@@ -0,0 +1,74 @@
+# Soulseek daemon (p2p file sharing with an emphasis on Music)
+# docs: <https://github.com/slskd/slskd/blob/master/docs/config.md>
+#
+# config precedence (higher precedence overrules lower precedence):
+# - Default Values < Environment Variables < YAML Configuraiton File < Command Line Arguments
+{ config, lib, ... }:
+{
+  sane.persist.sys.byStore.plaintext = [
+    { user = "slskd"; group = "slskd"; path = "/var/lib/slskd"; method = "bind"; }
+  ];
+  sops.secrets."slskd_env" = {
+    owner = config.users.users.slskd.name;
+    mode = "0400";
+  };
+
+  users.users.slskd.extraGroups = [ "media" ];
+
+  sane.ports.ports."50000" = {
+    protocol = [ "tcp" ];
+    # not visible to WAN: i run this in a separate netns
+    visibleTo.ovpn = true;
+    description = "colin-soulseek";
+  };
+
+  sane.dns.zones."uninsane.org".inet.CNAME."soulseek" = "native";
+
+  services.nginx.virtualHosts."soulseek.uninsane.org" = {
+    forceSSL = true;
+    enableACME = true;
+    locations."/" = {
+      proxyPass = "http://10.0.1.6:5001";
+      proxyWebsockets = true;
+    };
+  };
+
+  services.slskd.enable = true;
+  # env file, for auth (SLSKD_SLSK_PASSWORD, SLSKD_SLSK_USERNAME)
+  services.slskd.environmentFile = config.sops.secrets.slskd_env.path;
+  services.slskd.settings = {
+    soulseek.diagnostic_level = "Debug";  # one of "None"|"Warning"|"Info"|"Debug"
+    shares.directories = [
+      # folders to share
+      # syntax: <https://github.com/slskd/slskd/blob/master/docs/config.md#directories>
+      # [Alias]/path/on/disk
+      # NOTE: Music library is quick to scan; videos take a solid 10min to scan.
+      # TODO: re-enable the other libraries
+      # "[Audioooks]/var/lib/uninsane/media/Books/Audiobooks"
+      # "[Books]/var/lib/uninsane/media/Books/Books"
+      # "[Manga]/var/lib/uninsane/media/Books/Visual"
+      # "[games]/var/lib/uninsane/media/games"
+      "[Music]/var/lib/uninsane/media/Music"
+      # "[Film]/var/lib/uninsane/media/Videos/Film"
+      # "[Shows]/var/lib/uninsane/media/Videos/Shows"
+    ];
+    # directories.downloads = "..." # TODO
+    # directories.incomplete = "..." # TODO
+    # what unit is this? kbps??
+    global.upload.speed_limit = 32000;
+    web.logging = true;
+    # debug = true;
+    flags.no_logo = true;  # don't show logo at start
+    # flags.volatile = true;  # store searches and active transfers in RAM (completed transfers still go to disk). rec for btrfs/zfs
+  };
+
+  systemd.services.slskd = {
+    serviceConfig = {
+      # run this behind the OVPN static VPN
+      NetworkNamespacePath = "/run/netns/ovpns";
+      Restart = lib.mkForce "always";  # exits "success" when it fails to connect to soulseek server
+      RestartSec = "60s";
+      Group = "media";
+    };
+  };
+}
--- a/hosts/by-name/servo/services/transmission.nix
+++ b/hosts/by-name/servo/services/transmission.nix
@@ -1,14 +1,37 @@
-{ config, pkgs, ... }:
+{ config, lib, pkgs, ... }:

+let
+  # 2023/09/06: nixpkgs `transmission` defaults to old 3.00
+  # 2024/02/15: some torrent trackers whitelist clients; everyone is still on 3.00 for some reason :|
+  #             some do this via peer-id (e.g. baka); others via user-agent (e.g. MAM).
+  #             peer-id format is essentially the same between 3.00 and 4.x (just swap the MAJOR/MINOR/PATCH numbers).
+  #             user-agent format has changed. `Transmission/3.00` (old) v.s. `TRANSMISSION/MAJ.MIN.PATCH` (new).
+  realTransmission = pkgs.transmission_4;
+  realVersion = {
+    major = lib.versions.major realTransmission.version;
+    minor = lib.versions.minor realTransmission.version;
+    patch = lib.versions.patch realTransmission.version;
+  };
+  package = realTransmission.overrideAttrs (upstream: {
+    # `cmakeFlags = [ "-DTR_VERSION_MAJOR=3" ]`, etc, doesn't seem to take effect.
+    postPatch = (upstream.postPatch or "") + ''
+      substituteInPlace CMakeLists.txt \
+        --replace-fail 'TR_VERSION_MAJOR "${realVersion.major}"' 'TR_VERSION_MAJOR "3"' \
+        --replace-fail 'TR_VERSION_MINOR "${realVersion.minor}"' 'TR_VERSION_MINOR "0"' \
+        --replace-fail 'TR_VERSION_PATCH "${realVersion.patch}"' 'TR_VERSION_PATCH "0"' \
+        --replace-fail 'set(TR_USER_AGENT_PREFIX "''${TR_SEMVER}")' 'set(TR_USER_AGENT_PREFIX "3.00")'
+    '';
+  });
+in
 {
  sane.persist.sys.byStore.plaintext = [
    # TODO: mode? we need this specifically for the stats tracking in .config/
-    { user = "transmission"; group = config.users.users.transmission.group; path = "/var/lib/transmission"; }
+    { user = "transmission"; group = config.users.users.transmission.group; path = "/var/lib/transmission"; method = "bind"; }
  ];
  users.users.transmission.extraGroups = [ "media" ];

  services.transmission.enable = true;
-  services.transmission.package = pkgs.transmission_4;  #< 2023/09/06: nixpkgs `transmission` defaults to old 3.00
+  services.transmission.package = package;
  #v setting `group` this way doesn't tell transmission to `chown` the files it creates
  #  it's a nixpkgs setting which just runs the transmission daemon as this group
  services.transmission.group = "media";
@@ -16,10 +39,12 @@
  # transmission will by default not allow the world to read its files.
  services.transmission.downloadDirPermissions = "775";
  services.transmission.extraFlags = [
-    "--log-level=debug"
+    # "--log-level=debug"
  ];

  services.transmission.settings = {
+    # DOCUMENTATION/options list: <https://github.com/transmission/transmission/blob/main/docs/Editing-Configuration-Files.md#options>
+
    # message-level = 3;  #< enable for debug logging. 0-3, default is 2.
    # 0.0.0.0 => allow rpc from any host: we gate it via firewall and auth requirement
    rpc-bind-address = "0.0.0.0";
@@ -39,9 +64,9 @@
    encryption = 2;

    # units in kBps
-    speed-limit-down = 3000;
+    speed-limit-down = 12000;
    speed-limit-down-enabled = true;
-    speed-limit-up = 600;
+    speed-limit-up = 800;
    speed-limit-up-enabled = true;

    # see: https://git.zknt.org/mirror/transmission/commit/cfce6e2e3a9b9d31a9dafedd0bdc8bf2cdb6e876?lang=bg-BG
@@ -91,5 +116,10 @@
  };

  sane.dns.zones."uninsane.org".inet.CNAME."bt" = "native";
+  sane.ports.ports."51413" = {
+    protocol = [ "tcp" "udp" ];
+    visibleTo.ovpn = true;
+    description = "colin-bittorrent";
+  };
 }

--- a/hosts/by-name/servo/services/trust-dns.nix
+++ b/hosts/by-name/servo/services/trust-dns.nix
@@ -11,6 +11,8 @@ in lib.mkMerge [
  # don't bind to IPv6 until i explicitly test that stack
  services.trust-dns.settings.listen_addrs_ipv6 = [];
  services.trust-dns.quiet = true;
+  # FIXME(2023/11/26): services.trust-dns.debug doesn't log requests: use RUST_LOG=debug env for that.
+  # - see: <https://github.com/hickory-dns/hickory-dns/issues/2082>
  # services.trust-dns.debug = true;

  sane.ports.ports."53" = {
--- a/hosts/common/default.nix
+++ b/hosts/common/default.nix
@@ -1,4 +1,4 @@
-{ lib, pkgs, ... }:
+{ config, lib, pkgs, ... }:
 {
  imports = [
    ./feeds.nix
@@ -8,93 +8,52 @@
    ./hosts.nix
    ./ids.nix
    ./machine-id.nix
-    ./net.nix
-    ./nix-path
+    ./net
+    ./nix
    ./persist.nix
+    ./polyunfill.nix
    ./programs
    ./secrets.nix
    ./ssh.nix
+    ./systemd.nix
    ./users
-    ./vpn.nix
  ];

  sane.nixcache.enable-trusted-keys = true;
  sane.nixcache.enable = lib.mkDefault true;
  sane.persist.enable = lib.mkDefault true;
+  sane.root-on-tmpfs = lib.mkDefault true;
  sane.programs.sysadminUtils.enableFor.system = lib.mkDefault true;
  sane.programs.consoleUtils.enableFor.user.colin = lib.mkDefault true;

-  nixpkgs.config.allowUnfree = true;
-  nixpkgs.config.allowBroken = true;  # NIXPKGS_ALLOW_BROKEN
+  nixpkgs.config.allowUnfree = true;  # NIXPKGS_ALLOW_UNFREE=1
+  nixpkgs.config.allowBroken = true;  # NIXPKGS_ALLOW_BROKEN=1

  # time.timeZone = "America/Los_Angeles";
  time.timeZone = "Etc/UTC";  # DST is too confusing for me => use a stable timezone

-  # allow `nix flake ...` command
-  # TODO: is this still required?
-  nix.extraOptions = ''
-    experimental-features = nix-command flakes
-  '';
-  # hardlinks identical files in the nix store to save 25-35% disk space.
-  # unclear _when_ this occurs. it's not a service.
-  # does the daemon continually scan the nix store?
-  # does the builder use some content-addressed db to efficiently dedupe?
-  nix.settings.auto-optimise-store = true;
-
-  services.journald.extraConfig = ''
-    # docs: `man journald.conf`
-    # merged journald config is deployed to /etc/systemd/journald.conf
-    [Journal]
-    # disable journal compression because the underlying fs is compressed
-    Compress=no
-  '';
-
-  systemd.services.nix-daemon.serviceConfig = {
-    # the nix-daemon manages nix builders
-    # kill nix-daemon subprocesses when systemd-oomd detects an out-of-memory condition
-    # see:
-    # - nixos PR that enabled systemd-oomd: <https://github.com/NixOS/nixpkgs/pull/169613>
-    # - systemd's docs on these properties: <https://www.freedesktop.org/software/systemd/man/systemd.resource-control.html#ManagedOOMSwap=auto%7Ckill>
-    #
-    # systemd's docs warn that without swap, systemd-oomd might not be able to react quick enough to save the system.
-    # see `man oomd.conf` for further tunables that may help.
-    #
-    # alternatively, apply this more broadly with `systemd.oomd.enableSystemSlice = true` or `enableRootSlice`
-    # TODO: also apply this to the guest user's slice (user-1100.slice)
-    # TODO: also apply this to distccd
-    ManagedOOMMemoryPressure = "kill";
-    ManagedOOMSwap = "kill";
-  };
-
-
  system.activationScripts.nixClosureDiff = {
    supportsDryActivation = true;
    text = ''
      # show which packages changed versions or are new/removed in this upgrade
      # source: <https://github.com/luishfonseca/dotfiles/blob/32c10e775d9ec7cc55e44592a060c1c9aadf113e/modules/upgrade-diff.nix>
+      # modified to not error on boot (when /run/current-system doesn't exist)
+      if [ -d /run/current-system ]; then
        ${pkgs.nvd}/bin/nvd --nix-bin-dir=${pkgs.nix}/bin diff /run/current-system "$systemConfig"
+      fi
    '';
  };
-
-  # disable non-required packages like nano, perl, rsync, strace
-  environment.defaultPackages = [];
-
-  # dconf docs: <https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/desktop_migration_and_administration_guide/profiles>
-  # this lets programs temporarily write user-level dconf settings (aka gsettings).
-  # they're written to ~/.config/dconf/user, unless `DCONF_PROFILE` is set to something other than the default of /etc/dconf/profile/user
-  # find keys/values with `dconf dump /`
-  programs.dconf.enable = true;
-  programs.dconf.packages = [
-    (pkgs.writeTextFile {
-      name = "dconf-user-profile";
-      destination = "/etc/dconf/profile/user";
+  system.activationScripts.notifyActive = {
    text = ''
-        user-db:user
-        system-db:site
+      # send a notification to any sway users logged in, that the system has been activated/upgraded.
+      # this probably doesn't work if more than one sway session exists on the system.
+      _notifyActiveSwaySock="$(echo /run/user/*/sway-ipc*.sock)"
+      if [ -e "$_notifyActiveSwaySock" ]; then
+        SWAYSOCK="$_notifyActiveSwaySock" ${config.sane.programs.sway.packageUnwrapped}/bin/swaymsg -- exec \
+          "${pkgs.libnotify}/bin/notify-send 'nixos activated' 'version: $(cat $systemConfig/nixos-version)'"
+      fi
    '';
-    })
-  ];
-  # sane.programs.glib.enableFor.user.colin = true;  # for `gsettings`
+  };

  # link debug symbols into /run/current-system/sw/lib/debug
  # hopefully picked up by gdb automatically?
--- a/hosts/common/feeds.nix
+++ b/hosts/common/feeds.nix
@@ -1,4 +1,5 @@
 # where to find good stuff?
+# - universal search/directory: <https://podcastindex.org>
 # - podcasts w/ a community: <https://lemmyverse.net/communities?query=podcast>
 # - podcast rec thread: <https://lemmy.ml/post/1565858>
 #
@@ -50,6 +51,8 @@ let
        else
          "infrequent"
      ));
+    } // lib.optionalAttrs (lib.hasPrefix "https://www.youtube.com/" raw.url) {
+      format = "video";
    } // lib.optionalAttrs (raw.is_podcast or false) {
      format = "podcast";
    } // lib.optionalAttrs (raw.title or "" != "") {
@@ -60,6 +63,7 @@ let
    (fromDb "acquiredlpbonussecretsecret.libsyn.com" // tech)  # ACQ2 - more "Acquired" episodes
    (fromDb "allinchamathjason.libsyn.com" // pol)
    (fromDb "anchor.fm/s/34c7232c/podcast/rss" // tech)  # Civboot -- https://anchor.fm/civboot
+    (fromDb "anchor.fm/s/2da69154/podcast/rss" // tech)  # POD OF JAKE -- https://podofjake.com/
    (fromDb "cast.postmarketos.org" // tech)
    (fromDb "congressionaldish.libsyn.com" // pol)  # Jennifer Briney
    (fromDb "craphound.com" // pol)  # Cory Doctorow -- both podcast & text entries
@@ -69,21 +73,21 @@ let
    (fromDb "feeds.feedburner.com/80000HoursPodcast" // rat)
    (fromDb "feeds.feedburner.com/dancarlin/history" // rat)
    (fromDb "feeds.feedburner.com/radiolab" // pol)  # Radiolab -- also available here, but ONLY OVER HTTP: <http://feeds.wnyc.org/radiolab>
-    (fromDb "feeds.libsyn.com/421877" // rat)  # Less Wrong Curated
    (fromDb "feeds.megaphone.fm/behindthebastards" // pol)  # also Maggie Killjoy
-    (fromDb "feeds.megaphone.fm/hubermanlab" // uncat)  # Daniel Huberman on sleep
    (fromDb "feeds.megaphone.fm/recodedecode" // tech)  # The Verge - Decoder
    (fromDb "feeds.simplecast.com/54nAGcIl" // pol)  # The Daily
    (fromDb "feeds.simplecast.com/82FI35Px" // pol)  # Ezra Klein Show
    (fromDb "feeds.simplecast.com/wgl4xEgL" // rat)  # Econ Talk
    (fromDb "feeds.simplecast.com/xKJ93w_w" // uncat)  # Atlas Obscura
    (fromDb "feeds.transistor.fm/acquired" // tech)
+    (fromDb "fulltimenix.com" // tech)
    (fromDb "lexfridman.com/podcast" // rat)
    (fromDb "mapspodcast.libsyn.com" // uncat)  # Multidisciplinary Association for Psychedelic Studies
    (fromDb "omegataupodcast.net" // tech)  # 3/4 German; 1/4 eps are English
    (fromDb "omny.fm/shows/cool-people-who-did-cool-stuff" // pol)  # Maggie Killjoy -- referenced by Cory Doctorow
+    (fromDb "omny.fm/shows/the-dollop-with-dave-anthony-and-gareth-reynolds")  # The Dollop history/comedy
+    (fromDb "originstories.libsyn.com" // uncat)
    (fromDb "podcast.posttv.com/itunes/post-reports.xml" // pol)
-    (fromDb "podcast.thelinuxexp.com" // tech)
    (fromDb "politicalorphanage.libsyn.com" // pol)
    (fromDb "reverseengineering.libsyn.com/rss" // tech)  # UnNamed Reverse Engineering Podcast
    (fromDb "rss.acast.com/deconstructed")  # The Intercept - Deconstructed
@@ -92,17 +96,22 @@ let
    (fromDb "rss.art19.com/60-minutes" // pol)
    (fromDb "rss.art19.com/the-portal" // rat)  # Eric Weinstein
    (fromDb "seattlenice.buzzsprout.com" // pol)
+    (fromDb "srslywrong.com" // pol)
    (fromDb "sharkbytes.transistor.fm" // tech)  # Wireshark Podcast o_0
    (fromDb "sscpodcast.libsyn.com" // rat)  # Astral Codex Ten
    (fromDb "talesfromthebridge.buzzsprout.com" // tech)  # Sci-Fi? has Peter Watts; author of No Moods, Ads or Cutesy Fucking Icons (rifters.com)
    (fromDb "techwontsave.us" // pol)  # rec by Cory Doctorow
-    # (fromDb "trashfuturepodcast.podbean.com" // pol)  # rec by Cory Doctorow, but way rambly
    (fromDb "wakingup.libsyn.com" // pol)  # Sam Harris
    (fromDb "werenotwrong.fireside.fm" // pol)

+    # (fromDb "feeds.libsyn.com/421877" // rat)  # Less Wrong Curated
+    # (fromDb "feeds.megaphone.fm/hubermanlab" // uncat)  # Daniel Huberman on sleep
+    # (fromDb "feeds.simplecast.com/l2i9YnTd" // tech // pol)  # Hard Fork (NYtimes tech)
+    # (fromDb "podcast.thelinuxexp.com" // tech)  # low-brow linux/foss PR announcements
    # (fromDb "rss.art19.com/your-welcome" // pol)  # Michael Malice - Your Welcome -- also available here: <https://origin.podcastone.com/podcast?categoryID2=2232>
    # (fromDb "rss.prod.firstlook.media/deconstructed/podcast.rss" // pol)  #< possible URL rot
    # (fromDb "rss.prod.firstlook.media/intercepted/podcast.rss" // pol)  #< possible URL rot
+    # (fromDb "trashfuturepodcast.podbean.com" // pol)  # rec by Cory Doctorow, but way rambly
    # (mkPod "https://anchor.fm/s/21bc734/podcast/rss" // pol // infrequent)  # Emerge: making sense of what's next -- <https://www.whatisemerging.com/emergepodcast>
    # (mkPod "https://audioboom.com/channels/5097784.rss" // tech)  # Lateral with Tom Scott
    # (mkPod "https://feeds.megaphone.fm/RUNMED9919162779" // pol // infrequent)  # The Witch Trials of J.K. Rowling: <https://www.thefp.com/witchtrials>
@@ -110,135 +119,120 @@ let
  ];

  texts = [
-    # AGGREGATORS (> 1 post/day)
-    (fromDb "lwn.net" // tech)
-    # (fromDb "lesswrong.com" // rat)
+    (fromDb "acoup.blog/feed")  # history, states. author: <https://historians.social/@bretdevereaux/following>
+    (fromDb "amosbbatto.wordpress.com" // tech)
+    (fromDb "applieddivinitystudies.com" // rat)
+    (fromDb "artemis.sh" // tech)
+    (fromDb "ascii.textfiles.com" // tech)  # Jason Scott
+    (fromDb "austinvernon.site" // tech)
+    # (fromDb "balajis.com" // pol)  # Balaji
+    (fromDb "ben-evans.com/benedictevans" // pol)
+    (fromDb "bitbashing.io" // tech)
+    (fromDb "bitsaboutmoney.com" // uncat)
+    (fromDb "blog.danieljanus.pl" // tech)
+    (fromDb "blog.dshr.org" // pol)  # David Rosenthal
+    (fromDb "blog.jmp.chat" // tech)
+    (fromDb "blog.rust-lang.org" // tech)
+    (fromDb "blog.thalheim.io" // tech)  # Mic92
+    (fromDb "bunniestudios.com" // tech)  # Bunnie Juang
+    (fromDb "capitolhillseattle.com" // pol)
+    # (fromDb "drewdevault.com" // tech)
    # (fromDb "econlib.org" // pol)
-
-    # AGGREGATORS (< 1 post/day)
+    (fromDb "edwardsnowden.substack.com" // pol // text)
+    (fromDb "fasterthanli.me" // tech)
+    (fromDb "gwern.net" // rat)
+    (fromDb "harihareswara.net" // tech // pol)  # rec by Cory Doctorow
+    (fromDb "ianthehenry.com" // tech)
+    (fromDb "idiomdrottning.org" // uncat)
+    (fromDb "interconnected.org/home/feed" // rat)  # Matt Webb -- engineering-ish, but dreamy
+    (fromDb "jeffgeerling.com" // tech)
+    (fromDb "jefftk.com" // tech)
+    (fromDb "kill-the-newsletter.com/feeds/joh91bv7am2pnznv.xml" // pol)  # Matt Levine - Money Stuff
+    (fromDb "kosmosghost.github.io/index.xml" // tech)
+    # (fromDb "lesswrong.com" // rat)
+    (fromDb "linmob.net" // tech)
+    (fromDb "lwn.net" // tech)
+    (fromDb "lynalden.com" // pol)
+    (fromDb "mako.cc/copyrighteous" // tech // pol)  # rec by Cory Doctorow
+    (fromDb "mg.lol" // tech)
+    (fromDb "mindingourway.com" // rat)
+    (fromDb "morningbrew.com/feed" // pol)
+    (fromDb "overcomingbias.com" // rat)  # Robin Hanson
    (fromDb "palladiummag.com" // uncat)
+    (fromDb "philosopher.coach" // rat)  # Peter Saint-Andre -- side project of stpeter.im
+    (fromDb "pomeroyb.com" // tech)
+    (fromDb "preposterousuniverse.com" // rat)  # Sean Carroll
    (fromDb "profectusmag.com" // uncat)
+    (fromDb "project-insanity.org" // tech)  # shared blog by a few NixOS devs, notably onny
+    (fromDb "putanumonit.com" // rat)  # mostly dating topics. not advice, or humor, but looking through a social lens
+    (fromDb "richardcarrier.info" // rat)
+    (fromDb "rifters.com/crawl" // uncat)  # No Moods, Ads or Cutesy Fucking Icons
+    (fromDb "righto.com" // tech)  # Ken Shirriff
+    (fromDb "rootsofprogress.org" // rat)  # Jason Crawford
+    (fromDb "sagacioussuricata.com" // tech)  # ian (Sanctuary)
    (fromDb "semiaccurate.com" // tech)
-    (mkText "https://linuxphoneapps.org/blog/atom.xml" // tech // infrequent)
-    (fromDb "tuxphones.com" // tech)
+    (fromDb "sideways-view.com" // rat)  # Paul Christiano
+    (fromDb "slimemoldtimemold.com" // rat)
    (fromDb "spectrum.ieee.org" // tech)
+    (fromDb "stpeter.im/atom.xml" // pol)
    # (fromDb "theregister.com" // tech)
    (fromDb "thisweek.gnome.org" // tech)
-    # more nixos stuff here, but unclear how to subscribe: <https://nixos.org/blog/categories.html>
-    (mkText "https://nixos.org/blog/announcements-rss.xml" // tech // infrequent)
-    (mkText "https://nixos.org/blog/stories-rss.xml" // tech // weekly)
-    ## n.b.: quality RSS list here: <https://forum.merveilles.town/thread/57/share-your-rss-feeds%21-6/>
-    (mkText "https://forum.merveilles.town/rss.xml" // pol // infrequent)
-
-    ## No Moods, Ads or Cutesy Fucking Icons
-    (fromDb "rifters.com/crawl" // uncat)
-
-    # DEVELOPERS
-    (fromDb "blog.jmp.chat" // tech)
+    (fromDb "tuxphones.com" // tech)
    (fromDb "uninsane.org" // tech)
-    (fromDb "ascii.textfiles.com" // tech)  # Jason Scott
+    (fromDb "unintendedconsequenc.es" // rat)
+    # (fromDb "vitalik.ca" // tech)  # moved to vitalik.eth.limo
+    (fromDb "vitalik.eth.limo" // tech)  # Vitalik Buterin
+    (fromDb "webcurious.co.uk" // uncat)
    (fromDb "xn--gckvb8fzb.com" // tech)
-    (fromDb "amosbbatto.wordpress.com" // tech)
-    (fromDb "fasterthanli.me" // tech)
-    (fromDb "mg.lol" // tech)
-    # (fromDb "drewdevault.com" // tech)
-    ## Ken Shirriff
-    (fromDb "righto.com" // tech)
-    ## shared blog by a few NixOS devs, notably onny
-    (fromDb "project-insanity.org" // tech)
-    ## Vitalik Buterin
-    (fromDb "vitalik.ca" // tech)
-    ## ian (Sanctuary)
-    (fromDb "sagacioussuricata.com" // tech)
-    (fromDb "artemis.sh" // tech)
-    ## Bunnie Juang
-    (fromDb "bunniestudios.com" // tech)
-    (fromDb "blog.danieljanus.pl" // tech)
-    (fromDb "ianthehenry.com" // tech)
-    (fromDb "bitbashing.io" // tech)
-    (fromDb "idiomdrottning.org" // uncat)
-    (mkText "http://boginjr.com/feed" // tech // infrequent)
-    (mkText "https://anish.lakhwara.com/home.html" // tech // weekly)
-    (fromDb "jefftk.com" // tech)
-    (fromDb "pomeroyb.com" // tech)
-    (fromDb "harihareswara.net" // tech // pol)  # rec by Cory Doctorow
-    (fromDb "mako.cc/copyrighteous" // tech // pol)  # rec by Cory Doctorow
-    # (mkText "https://til.simonwillison.net/tils/feed.atom" // tech // weekly)
-
-    # TECH PROJECTS
-    (fromDb "blog.rust-lang.org" // tech)
-
-    # (TECH; POL) COMMENTATORS
-    ## Matt Webb -- engineering-ish, but dreamy
-    (fromDb "interconnected.org/home/feed" // rat)
-    (fromDb "edwardsnowden.substack.com" // pol // text)
-    ## Julia Evans
-    (mkText "https://jvns.ca/atom.xml" // tech // weekly)
-    (mkText "http://benjaminrosshoffman.com/feed" // pol // weekly)
-    ## Ben Thompson
-    (mkText "https://www.stratechery.com/rss" // pol // weekly)
-    ## Balaji
-    (fromDb "balajis.com" // pol)
-    (fromDb "ben-evans.com/benedictevans" // pol)
-    (fromDb "lynalden.com" // pol)
-    (fromDb "austinvernon.site" // tech)
-    (mkSubstack "oversharing" // pol // daily)
+    (mkSubstack "astralcodexten" // rat // daily)  # Scott Alexander
    (mkSubstack "byrnehobart" // pol // infrequent)
    # (mkSubstack "doomberg" // tech // weekly)  # articles are all pay-walled
-    ## David Rosenthal
-    (fromDb "blog.dshr.org" // pol)
-    ## Matt Levine
-    (mkText "https://www.bloomberg.com/opinion/authors/ARbTQlRLRjE/matthew-s-levine.rss" // pol // weekly)
-    (fromDb "stpeter.im/atom.xml" // pol)
-    ## Peter Saint-Andre -- side project of stpeter.im
-    (fromDb "philosopher.coach" // rat)
-    (fromDb "morningbrew.com/feed" // pol)
-
-    # RATIONALITY/PHILOSOPHY/ETC
-    (mkSubstack "samkriss" // humor // infrequent)
-    (fromDb "unintendedconsequenc.es" // rat)
-    (fromDb "applieddivinitystudies.com" // rat)
-    (fromDb "slimemoldtimemold.com" // rat)
-    (fromDb "richardcarrier.info" // rat)
-    (fromDb "gwern.net" // rat)
-    ## Jason Crawford
-    (fromDb "rootsofprogress.org" // rat)
-    ## Robin Hanson
-    (fromDb "overcomingbias.com" // rat)
-    ## Scott Alexander
-    (mkSubstack "astralcodexten" // rat // daily)
-    ## Paul Christiano
-    (fromDb "sideways-view.com" // rat)
-    ## Sean Carroll
-    (fromDb "preposterousuniverse.com" // rat)
    (mkSubstack "eliqian" // rat // weekly)
-    (mkText "https://acoup.blog/feed" // rat // weekly)
-    (fromDb "mindingourway.com" // rat)
-
-    ## mostly dating topics. not advice, or humor, but looking through a social lens
-    (fromDb "putanumonit.com" // rat)
-
-    # LOCAL
-    (fromDb "capitolhillseattle.com" // pol)
-
-    # CODE
+    (mkSubstack "oversharing" // pol // daily)
+    (mkSubstack "samkriss" // humor // infrequent)
+    (mkText "http://benjaminrosshoffman.com/feed" // pol // weekly)
+    (mkText "http://boginjr.com/feed" // tech // infrequent)
+    (mkText "https://anish.lakhwara.com/home.html" // tech // weekly)
+    (mkText "https://forum.merveilles.town/rss.xml" // pol // infrequent)  #quality RSS list here: <https://forum.merveilles.town/thread/57/share-your-rss-feeds%21-6/>
    # (mkText "https://github.com/Kaiteki-Fedi/Kaiteki/commits/master.atom" // tech // infrequent)
+    (mkText "https://jvns.ca/atom.xml" // tech // weekly)  # Julia Evans
+    (mkText "https://linuxphoneapps.org/blog/atom.xml" // tech // infrequent)
+    (mkText "https://nixos.org/blog/announcements-rss.xml" // tech // infrequent)  # more nixos stuff here, but unclear how to subscribe: <https://nixos.org/blog/categories.html>
+    (mkText "https://nixos.org/blog/stories-rss.xml" // tech // weekly)
+    # (mkText "https://til.simonwillison.net/tils/feed.atom" // tech // weekly)
+    # (mkText "https://www.bloomberg.com/opinion/authors/ARbTQlRLRjE/matthew-s-levine.rss" // pol // weekly)  # Matt Levine (preview/paywalled)
+    (mkText "https://www.stratechery.com/rss" // pol // weekly)  # Ben Thompson
+  ];
+
+  videos = [
+    (fromDb "youtube.com/@Channel5YouTube" // pol)
+    (fromDb "youtube.com/@ColdFusion")
+    (fromDb "youtube.com/@ContraPoints" // pol)
+    (fromDb "youtube.com/@Exurb1a")
+    (fromDb "youtube.com/@hbomberguy")
+    (fromDb "youtube.com/@JackStauber")
+    (fromDb "youtube.com/@PolyMatter")
+    # (fromDb "youtube.com/@rossmanngroup" // pol // tech)  # Louis Rossmann
+    (fromDb "youtube.com/@TechnologyConnections" // tech)
+    (fromDb "youtube.com/@TheB1M")
+    (fromDb "youtube.com/@TomScottGo")
+    (fromDb "youtube.com/@Vihart")
+    (fromDb "youtube.com/@Vox")
+    (fromDb "youtube.com/@Vsauce")
  ];

  images = [
-    (fromDb "smbc-comics.com" // img // humor)
-    (fromDb "xkcd.com" // img // humor)
-    (fromDb "turnoff.us" // img // humor)
-    (fromDb "pbfcomics.com" // img // humor)
-    # (mkImg "http://dilbert.com/feed" // humor // daily)
-    (fromDb "poorlydrawnlines.com/feed" // img // humor)
-
-    # ART
+    (fromDb "catandgirl.com" // img // humor)
    (fromDb "miniature-calendar.com" // img // art // daily)
+    (fromDb "pbfcomics.com" // img // humor)
+    (fromDb "poorlydrawnlines.com/feed" // img // humor)
+    (fromDb "smbc-comics.com" // img // humor)
+    (fromDb "turnoff.us" // img // humor)
+    (fromDb "xkcd.com" // img // humor)
  ];
 in
 {
-  sane.feeds = texts ++ images ++ podcasts;
+  sane.feeds = texts ++ images ++ podcasts ++ videos;

  assertions = builtins.map
    (p: {
--- a/hosts/common/fs.nix
+++ b/hosts/common/fs.nix
@@ -1,5 +1,6 @@
 # docs
 # - x-systemd options: <https://www.freedesktop.org/software/systemd/man/systemd.mount.html>
+# - fuse options: `man mount.fuse`

 { lib, pkgs, sane-lib, ... }:

@@ -8,13 +9,22 @@ let
    common = [
      "_netdev"
      "noatime"
-      "user"  # allow any user with access to the device to mount the fs
+      # user: allow any user with access to the device to mount the fs.
+      #       note that this requires a suid `mount` binary; see: <https://zameermanji.com/blog/2022/8/5/using-fuse-without-root-on-linux/>
+      "user"
      "x-systemd.requires=network-online.target"
      "x-systemd.after=network-online.target"
      "x-systemd.mount-timeout=10s"  # how long to wait for mount **and** how long to wait for unmount
    ];
-    auto = [ "x-systemd.automount" ];
-    noauto = [ "noauto" ];  # don't mount as part of remote-fs.target
+    # x-systemd.automount: mount the fs automatically *on first access*.
+    # creates a `path-to-mount.automount` systemd unit.
+    automount = [ "x-systemd.automount" ];
+    # noauto: don't mount as part of remote-fs.target.
+    # N.B.: `remote-fs.target` is a dependency of multi-user.target, itself of graphical.target.
+    # hence, omitting `noauto` can slow down boots.
+    noauto = [ "noauto" ];
+    # lazyMount: defer mounting until first access from userspace
+    lazyMount = noauto ++ automount;
    wg = [
      "x-systemd.requires=wireguard-wg-home.service"
      "x-systemd.after=wireguard-wg-home.service"
@@ -22,19 +32,34 @@ let

    ssh = common ++ [
      "identityfile=/home/colin/.ssh/id_ed25519"
-      "allow_other"
+      "allow_other"  # allow users other than the one who mounts it to access it. needed, if systemd is the one mounting this fs (as root)
+      # allow_root: allow root to access files on this fs (if mounted by non-root, else it can always access them).
+      #             N.B.: if both allow_root and allow_other are specified, then only allow_root takes effect.
+      # "allow_root"
+      # default_permissions: enforce local permissions check. CRUCIAL if using `allow_other`.
+      # w/o this, permissions mode of sshfs is like:
+      # - sshfs runs all remote commands as the remote user.
+      # - if a local user has local permissions to the sshfs mount, then their file ops are sent blindly across the tunnel.
+      # - `allow_other` allows *any* local user to access the mount, and hence any local user can now freely become the remote mapped user.
+      # with default_permissions, sshfs doesn't tunnel file ops from users until checking that said user could perform said op on an equivalent local fs.
      "default_permissions"
    ];
    sshColin = ssh ++ [
+      # follow_symlinks: remote files which are symlinks are presented to the local system as ordinary files (as the target of the symlink).
+      #                  if the symlink target does not exist, the presentation is unspecified.
+      #                  symlinks which point outside the mount ARE followed. so this is more capable than `transform_symlinks`
+      "follow_symlinks"
+      # symlinks on the remote fs which are absolute paths are presented to the local system as relative symlinks pointing to the expected data on the remote fs.
+      # only symlinks which would point inside the mountpoint are translated.
      "transform_symlinks"
      "idmap=user"
      "uid=1000"
      "gid=100"
    ];
-    sshRoot = ssh ++ [
-      # we don't transform_symlinks because that breaks the validity of remote /nix stores
-      "sftp_server=/run/wrappers/bin/sudo\\040/run/current-system/sw/libexec/sftp-server"
-    ];
+    # sshRoot = ssh ++ [
+    #   # we don't transform_symlinks because that breaks the validity of remote /nix stores
+    #   "sftp_server=/run/wrappers/bin/sudo\\040/run/current-system/sw/libexec/sftp-server"
+    # ];
    # in the event of hunt NFS mounts, consider:
    # - <https://unix.stackexchange.com/questions/31979/stop-broken-nfs-mounts-from-locking-a-directory>

@@ -57,13 +82,17 @@ let
    ];
  };
  remoteHome = host: {
-    fileSystems."/mnt/${host}-home" = {
+    fileSystems."/mnt/${host}/home" = {
      device = "colin@${host}:/home/colin";
      fsType = "fuse.sshfs";
-      options = fsOpts.sshColin ++ fsOpts.noauto;
+      options = fsOpts.sshColin ++ fsOpts.lazyMount;
      noCheck = true;
    };
-    sane.fs."/mnt/${host}-home" = sane-lib.fs.wantedDir;
+    sane.fs."/mnt/${host}/home" = sane-lib.fs.wanted {
+      dir.acl.user = "colin";
+      dir.acl.group = "users";
+      dir.acl.mode = "0700";
+    };
  };
 in
 lib.mkMerge [
@@ -103,34 +132,38 @@ lib.mkMerge [
    #   device = "servo-hn:/";
    #   noCheck = true;
    #   fsType = "nfs";
-    #   options = fsOpts.nfs ++ fsOpts.auto ++ fsOpts.wg;
+    #   options = fsOpts.nfs ++ fsOpts.automount ++ fsOpts.wg;
    # };
-    fileSystems."/mnt/servo-nfs/media" = {
+    fileSystems."/mnt/servo/media" = {
      device = "servo-hn:/media";
      noCheck = true;
      fsType = "nfs";
-      options = fsOpts.nfs ++ fsOpts.auto ++ fsOpts.wg;
+      options = fsOpts.nfs ++ fsOpts.lazyMount ++ fsOpts.wg;
    };
-    fileSystems."/mnt/servo-nfs/playground" = {
+    sane.fs."/mnt/servo/media" = sane-lib.fs.wanted {
+      dir.acl.user = "colin";
+      dir.acl.group = "users";
+      dir.acl.mode = "0750";
+    };
+    fileSystems."/mnt/servo/playground" = {
      device = "servo-hn:/playground";
      noCheck = true;
      fsType = "nfs";
-      options = fsOpts.nfs ++ fsOpts.auto ++ fsOpts.wg;
+      options = fsOpts.nfs ++ fsOpts.lazyMount ++ fsOpts.wg;
+    };
+    sane.fs."/mnt/servo/playground" = sane-lib.fs.wanted {
+      dir.acl.user = "colin";
+      dir.acl.group = "users";
+      dir.acl.mode = "0750";
    };
-    # fileSystems."/mnt/servo-media-nfs" = {
-    #   device = "servo-hn:/media";
-    #   noCheck = true;
-    #   fsType = "nfs";
-    #   options = fsOpts.common ++ fsOpts.auto;
-    # };
-    sane.fs."/mnt/servo-media" = sane-lib.fs.wantedSymlinkTo "/mnt/servo-nfs/media";

-    environment.pathsToLink = [
-      # needed to achieve superuser access for user-mounted filesystems (see optionsRoot above)
-      # we can only link whole directories here, even though we're only interested in pkgs.openssh
-      "/libexec"
-    ];
+    # environment.pathsToLink = [
+    #   # needed to achieve superuser access for user-mounted filesystems (see sshRoot above)
+    #   # we can only link whole directories here, even though we're only interested in pkgs.openssh
+    #   "/libexec"
+    # ];

+    programs.fuse.userAllowOther = true;  #< necessary for `allow_other` or `allow_root` options.
    environment.systemPackages = [
      pkgs.sshfs-fuse
    ];
--- a/hosts/common/hardware/default.nix
+++ b/hosts/common/hardware/default.nix
@@ -1,4 +1,4 @@
-{ lib, pkgs, ... }:
+{ config, lib, pkgs, ... }:

 {
  imports = [
@@ -12,8 +12,9 @@
    copy_bin_and_libs ${pkgs.util-linux}/bin/{cfdisk,lsblk,lscpu}
    copy_bin_and_libs ${pkgs.gptfdisk}/bin/{cgdisk,gdisk}
    copy_bin_and_libs ${pkgs.smartmontools}/bin/smartctl
-    copy_bin_and_libs ${pkgs.nvme-cli}/bin/nvme
    copy_bin_and_libs ${pkgs.e2fsprogs}/bin/resize2fs
+  '' + lib.optionalString pkgs.stdenv.hostPlatform.isx86_64 ''
+    copy_bin_and_libs ${pkgs.nvme-cli}/bin/nvme  # doesn't cross compile
  '';
  boot.kernelParams = [
    "boot.shell_on_fail"
@@ -27,6 +28,13 @@
  #   "systemd.log_level=debug"
  #   "systemd.log_target=console"

+  # moby has to run recent kernels (defined elsewhere).
+  # meanwhile, kernel variation plays some minor role in things like sandboxing (landlock) and capabilities.
+  # simpler to keep near the latest kernel on all devices,
+  # and also makes certain that any weird system-level bugs i see aren't likely to be stale kernel bugs.
+  # servo needs zfs though, which doesn't support every kernel.
+  boot.kernelPackages = lib.mkDefault pkgs.zfs.latestCompatibleLinuxPackages;
+
  # hack in the `boot.shell_on_fail` arg since that doesn't always seem to work.
  boot.initrd.preFailCommands = "allowShell=1";

@@ -39,6 +47,12 @@
  # non-free firmware
  hardware.enableRedistributableFirmware = true;

+  # default is 252274, which is too low particularly for servo.
+  # manifests as spurious "No space left on device" when trying to install watches,
+  # e.g. in dyn-dns by `systemctl start dyn-dns-watcher.path`.
+  # see: <https://askubuntu.com/questions/828779/failed-to-add-run-systemd-ask-password-to-directory-watch-no-space-left-on-dev>
+  boot.kernel.sysctl."fs.inotify.max_user_watches" = 1048576;
+
  # powertop will default to putting USB devices -- including HID -- to sleep after TWO SECONDS
  powerManagement.powertop.enable = false;
  # linux CPU governor: <https://www.kernel.org/doc/Documentation/cpu-freq/governors.txt>
@@ -57,10 +71,19 @@
  powerManagement.cpuFreqGovernor = "ondemand";

  services.logind.extraConfig = ''
-    # don’t shutdown when power button is short-pressed
-    HandlePowerKey=ignore
+    # see: `man logind.conf`
+    # don’t shutdown when power button is short-pressed (commonly done an accident, or by cats).
+    #   but do on long-press: useful to gracefully power-off server.
+    HandlePowerKey=lock
+    HandlePowerKeyLongPress=poweroff
+    HandleLidSwitch=lock
  '';

+  # some packages build only if binfmt *isn't* present
+  nix.settings.system-features = lib.mkIf (config.boot.binfmt.emulatedSystems == []) [
+    "no-binfmt"
+  ];
+
  # services.snapper.configs = {
  #   root = {
  #     subvolume = "/";
--- a/hosts/common/home/default.nix
+++ b/hosts/common/home/default.nix
@@ -1,7 +1,7 @@
 { ... }:
 {
  imports = [
-    ./keyring
+    ./fs.nix
    ./mime.nix
    ./ssh.nix
    ./xdg-dirs.nix
--- a/hosts/common/home/fs.nix
+++ b/hosts/common/home/fs.nix
@@ -0,0 +1,42 @@
+{ config, ... }:
+{
+  sane.user.persist.byStore.plaintext = [
+    "archive"
+    "dev"
+    # TODO: records should be private
+    "records"
+    "ref"
+    "tmp"
+    "use"
+    "Books/local"
+    "Music"
+    "Pictures/albums"
+    "Pictures/cat"
+    "Pictures/from"
+    "Pictures/Screenshots"  #< XXX: something is case-sensitive about this?
+    "Pictures/Photos"
+    "Videos/local"
+
+    # these are persisted simply to save on RAM.
+    # ~/.cache/nix can become several GB.
+    # mesa_shader_cache is < 10 MB.
+    # TODO: integrate with sane.programs.sandbox?
+    ".cache/mesa_shader_cache"
+    ".cache/nix"
+  ];
+  sane.user.persist.byStore.private = [
+    "knowledge"
+  ];
+
+  # convenience
+  sane.user.fs.".persist/private".symlink.target = config.sane.persist.stores.private.origin;
+  sane.user.fs.".persist/plaintext".symlink.target = config.sane.persist.stores.plaintext.origin;
+  sane.user.fs.".persist/ephemeral".symlink.target = config.sane.persist.stores.cryptClearOnBoot.origin;
+
+  sane.user.fs."nixos".symlink.target = "dev/nixos";
+
+  sane.user.fs."Books/servo".symlink.target = "/mnt/servo/media/Books";
+  sane.user.fs."Videos/servo".symlink.target = "/mnt/servo/media/Videos";
+  # sane.user.fs."Music/servo".symlink.target = "/mnt/servo/media/Music";
+  sane.user.fs."Pictures/servo-macros".symlink.target = "/mnt/servo/media/Pictures/macros";
+}
--- a/hosts/common/home/keyring/default.nix
+++ b/hosts/common/home/keyring/default.nix
@@ -1,17 +0,0 @@
-{ config, pkgs, sane-lib, ... }:
-
-let
-  init-keyring = pkgs.static-nix-shell.mkBash {
-    pname = "init-keyring";
-    src = ./.;
-  };
-in
-{
-  sane.user.persist.byStore.private = [ ".local/share/keyrings" ];
-
-  sane.user.fs."private/.local/share/keyrings/default" = {
-    generated.command = [ "${init-keyring}/bin/init-keyring" ];
-    wantedBy = [ config.sane.fs."/home/colin/private".unit ];
-    wantedBeforeBy = [ ];  # don't created this as part of `multi-user.target`
-  };
-}
--- a/hosts/common/home/keyring/init-keyring
+++ b/hosts/common/home/keyring/init-keyring
@@ -1,21 +0,0 @@
-#!/usr/bin/env nix-shell
-#!nix-shell -i bash
-# initializes the default libsecret keyring (used by gnome-keyring) if not already initialized.
-# this initializes it to be plaintext/unencrypted.
-
-ringdir=/home/colin/private/.local/share/keyrings
-if test -f "$ringdir/default"
-then
-  echo 'keyring already initialized: not doing anything'
-else
-  keyring="$ringdir/Default_keyring.keyring"
-
-  echo 'initializing default user keyring:' "$keyring.new"
-  echo '[keyring]' > "$keyring.new"
-  echo 'display-name=Default keyring' >> "$keyring.new"
-  echo 'lock-on-idle=false' >> "$keyring.new"
-  echo 'lock-after=false' >> "$keyring.new"
-  chown colin:users "$keyring.new"
-  # closest to an atomic update we can achieve
-  mv "$keyring.new" "$keyring" && echo -n "Default_keyring" > "$ringdir/default"
-fi
--- a/hosts/common/home/mime.nix
+++ b/hosts/common/home/mime.nix
@@ -1,28 +1,94 @@
-{ config, lib, ...}:
+# TODO: move into modules/users.nix
+{ config, lib, pkgs, ...}:

 let
-  # ProgramConfig -> { "<mime-type>" = { priority, desktop }; }
-  weightedMimes = prog: builtins.mapAttrs (_key: desktop: { priority = prog.mime.priority; desktop = desktop; }) prog.mime.associations;
-  # [ { "<mime-type>" = { priority, desktop } ]; } ] -> { "<mime-type>" = [ { priority, desktop } ... ]; }
-  mergeMimes = mimes: lib.foldAttrs (item: acc: [item] ++ acc) [] mimes;
-  # [ { priority, desktop } ... ] -> Self
-  sortOneMimeType = associations: builtins.sort (l: r: assert l.priority != r.priority; l.priority < r.priority) associations;
-  sortMimes = mimes: builtins.mapAttrs (_k: sortOneMimeType) mimes;
-  removePriorities = mimes: builtins.mapAttrs (_k: associations: builtins.map (a: a.desktop) associations) mimes;
+  # [ ProgramConfig ]
+  enabledPrograms = builtins.filter
+    (p: p.enabled)
+    (builtins.attrValues config.sane.programs);

  # [ ProgramConfig ]
-  enabledPrograms = builtins.filter (p: p.enabled) (builtins.attrValues config.sane.programs);
+  enabledProgramsWithPackage = builtins.filter (p: p.package != null) enabledPrograms;
+
  # [ { "<mime-type>" = { prority, desktop } ]
  enabledWeightedMimes = builtins.map weightedMimes enabledPrograms;
+
+  # ProgramConfig -> { "<mime-type>" = { priority, desktop }; }
+  weightedMimes = prog: builtins.mapAttrs
+    (_key: desktop: {
+      priority = prog.mime.priority; desktop = desktop;
+    })
+    prog.mime.associations;
+
+  # [ { "<mime-type>" = { priority, desktop } ]; } ] -> { "<mime-type>" = [ { priority, desktop } ... ]; }
+  mergeMimes = mimes: lib.foldAttrs (item: acc: [item] ++ acc) [] mimes;
+
+  # [ { priority, desktop } ... ] -> Self
+  sortOneMimeType = associations: builtins.sort
+    (l: r: lib.throwIf
+      (l.priority == r.priority)
+      "${l.desktop} and ${r.desktop} share a preferred mime type with identical priority ${builtins.toString l.priority} (and so the desired association is ambiguous)"
+      (l.priority < r.priority)
+    )
+    associations;
+  sortMimes = mimes: builtins.mapAttrs (_k: sortOneMimeType) mimes;
+  # { "<mime-type>"} = [ { priority, desktop } ... ]; } -> { "<mime-type>" = [ "<desktop>" ... ]; }
+  removePriorities = mimes: builtins.mapAttrs
+    (_k: associations: builtins.map (a: a.desktop) associations)
+    mimes;
+  # { "<mime-type>" = [ "<desktop>" ... ]; } -> { "<mime-type>" = "<desktop1>;<desktop2>;..."; }
+  formatDesktopLists = mimes: builtins.mapAttrs
+    (_k: desktops: lib.concatStringsSep ";" desktops)
+    mimes;
+
+  mimeappsListPkg = pkgs.writeTextDir "share/applications/mimeapps.list" (
+    lib.generators.toINI { } {
+      "Default Applications" = formatDesktopLists (removePriorities (sortMimes (mergeMimes enabledWeightedMimes)));
+    }
+  );
+
+  localShareApplicationsPkg = (pkgs.symlinkJoin {
+    name = "user-local-share-applications";
+    paths = builtins.map
+      (p: "${p.package}")
+      (enabledProgramsWithPackage ++ [ { package=mimeappsListPkg; } ]);
+  }).overrideAttrs (orig: {
+    # like normal symlinkJoin, but don't error if the path doesn't exist
+    buildCommand = ''
+      mkdir -p $out/share/applications
+      for i in $(cat $pathsPath); do
+        if [ -e "$i/share/applications" ]; then
+          ${pkgs.buildPackages.xorg.lndir}/bin/lndir -silent $i/share/applications $out/share/applications
+        fi
+      done
+      runHook postBuild
+    '';
+    postBuild = ''
+      # rebuild `mimeinfo.cache`, used by file openers to show the list of *all* apps, not just the user's defaults.
+      ${pkgs.buildPackages.desktop-file-utils}/bin/update-desktop-database $out/share/applications
+    '';
+  });
+
 in
 {
  # the xdg mime type for a file can be found with:
  # - `xdg-mime query filetype path/to/thing.ext`
  # the default handler for a mime type can be found with:
  # - `xdg-mime query default <mimetype>`  (e.g. x-scheme-handler/http)
+  # the nix-configured handler can be found `nix-repl > :lf . > hostConfigs.desko.xdg.mime.defaultApplications`
+  #
+  # glib/gio is queried via glib.bin output:
+  # - `gio mime x-scheme-handler/https`
+  # - `gio open <path_or_url>`
+  # - `gio launch </path/to/app.desktop>`
  #
  # we can have single associations or a list of associations.
  # there's also options to *remove* [non-default] associations from specific apps
-  xdg.mime.enable = true;
-  xdg.mime.defaultApplications = removePriorities (sortMimes (mergeMimes enabledWeightedMimes));
+  # N.B.: don't use nixos' `xdg.mime` option becaue that caues `/share/applications` to be linked into the whole system,
+  # which limits what i can do around sandboxing. getting the default associations to live in ~/ makes it easier to expose
+  # the associations to apps selectively.
+  # xdg.mime.enable = true;
+  # xdg.mime.defaultApplications = removePriorities (sortMimes (mergeMimes enabledWeightedMimes));
+
+  sane.user.fs.".local/share/applications".symlink.target = "${localShareApplicationsPkg}/share/applications";
 }
--- a/hosts/common/hosts.nix
+++ b/hosts/common/hosts.nix
@@ -19,7 +19,7 @@
  };

  sane.hosts.by-name."moby" = {
-    ssh.authorized = lib.mkDefault false;  # moby's too easy to hijack: don't let it ssh places
+    # ssh.authorized = lib.mkDefault false;  # moby's too easy to hijack: don't let it ssh places
    ssh.user_pubkey = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAICrR+gePnl0nV/vy7I5BzrGeyVL+9eOuXHU1yNE3uCwU";
    ssh.host_pubkey = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIO1N/IT3nQYUD+dBlU1sTEEVMxfOyMkrrDeyHcYgnJvw";
    wg-home.pubkey = "I7XIR1hm8bIzAtcAvbhWOwIAabGkuEvbWH/3kyIB1yA=";
--- a/hosts/common/ids.nix
+++ b/hosts/common/ids.nix
@@ -49,6 +49,16 @@
  sane.ids.media.gid = 2414;
  sane.ids.ntfy-sh.uid = 2415;
  sane.ids.ntfy-sh.gid = 2415;
+  sane.ids.monero.uid = 2416;
+  sane.ids.monero.gid = 2416;
+  sane.ids.slskd.uid = 2417;
+  sane.ids.slskd.gid = 2417;
+  sane.ids.bitcoind-mainnet.uid = 2418;
+  sane.ids.bitcoind-mainnet.gid = 2418;
+  sane.ids.clightning.uid = 2419;
+  sane.ids.clightning.gid = 2419;
+  sane.ids.nix-serve.uid = 2420;
+  sane.ids.nix-serve.gid = 2420;

  sane.ids.colin.uid = 1000;
  sane.ids.guest.uid = 1100;
@@ -63,6 +73,8 @@
  sane.ids.systemd-oom.uid = 2005;
  sane.ids.systemd-oom.gid = 2005;
  sane.ids.wireshark.gid = 2006;
+  sane.ids.nixremote.uid = 2007;
+  sane.ids.nixremote.gid = 2007;

  # found on graphical hosts
  sane.ids.nm-iodine.uid = 2101;  # desko/moby/lappy
--- a/hosts/common/net/default.nix
+++ b/hosts/common/net/default.nix
@@ -1,6 +1,30 @@
 { lib, ... }:

 {
+  imports = [
+    ./dns.nix
+    ./hostnames.nix
+    ./upnp.nix
+    ./vpn.nix
+  ];
+
+  systemd.network.enable = true;
+  networking.useNetworkd = true;
+
+  # view refused/dropped packets with: `sudo journalctl -k`
+  # networking.firewall.logRefusedPackets = true;
+  # networking.firewall.logRefusedUnicastsOnly = false;
+  networking.firewall.logReversePathDrops = true;
+  # linux will drop inbound packets if it thinks a reply to that packet wouldn't exit via the same interface (rpfilter).
+  #   that heuristic fails for complicated VPN-style routing, especially with SNAT.
+  # networking.firewall.checkReversePath = false;  # or "loose" to keep it partially.
+  # networking.firewall.enable = false;  #< set false to debug
+
+  # this is needed to forward packets from the VPN to the host.
+  # this is required separately by servo and by any `sane-vpn` users,
+  # however Nix requires this be set centrally, in only one location (i.e. here)
+  boot.kernel.sysctl."net.ipv4.ip_forward" = 1;
+
  # the default backend is "wpa_supplicant".
  # wpa_supplicant reliably picks weak APs to connect to.
  # see: <https://gitlab.freedesktop.org/NetworkManager/NetworkManager/-/issues/474>
@@ -35,10 +59,6 @@
  # e.g. openconnect drags in webkitgtk (for SSO)!
  networking.networkmanager.plugins = lib.mkForce [];

-  networking.firewall.allowedUDPPorts = [
-    1900  # to received UPnP advertisements. required by sane-ip-check-upnp
-  ];
-
  # keyfile.path = where networkmanager should look for connection credentials
  networking.networkmanager.extraConfig = ''
    [keyfile]
--- a/hosts/common/net/dns.nix
+++ b/hosts/common/net/dns.nix
@@ -0,0 +1,67 @@
+# things to consider when changing these parameters:
+# - temporary VPN access (`sane-vpn up ...`)
+# - servo `ovpns` namespace (it *relies* on /etc/resolv.conf mentioning 127.0.0.53)
+# - jails: `firejail --net=br-ovpnd-us --noprofile --dns=46.227.67.134 ping 1.1.1.1`
+#
+# components:
+# - /etc/nsswitch.conf:
+#   - glibc uses this to provide `getaddrinfo`, i.e. host -> ip address lookup
+#     call directly with `getent ahostsv4 www.google.com`
+#   - `nss` (a component of glibc) is modular: names mentioned in that file are `dlopen`'d (i think that's the mechanism)
+#     in NixOS, that means _they have to be on LDPATH_.
+#   - `nscd` is used by NixOS simply to proxy nss requests.
+#      here, /etc/nsswitch.conf consumers contact nscd via /var/run/nscd/socket.
+#      in this way, only `nscd` needs to have the nss modules on LDPATH.
+# - /etc/resolv.conf
+#   - contains the DNS servers for a system.
+#   - historically, NetworkManager would update this file as you switch networks.
+#   - modern implementations hardcodes `127.0.0.53` and then systemd-resolved proxies everything (and caches).
+#
+# namespacing:
+# - each namespace can use a different /etc/resolv.conf to specify different DNS servers (see `firejail --dns=...`)
+# - nscd breaks namespacing: the host nscd is unaware of the guest's /etc/resolv.conf, and so direct's the guest's DNS requests to the host's servers.
+#   - this is fixed by either `firejail --blacklist=/var/run/nscd/socket`, or disabling nscd altogether.
+{ lib, ... }:
+{
+  # use systemd's stub resolver.
+  # /etc/resolv.conf isn't sophisticated enough to use different servers per net namespace (or link).
+  # instead, running the stub resolver on a known address in the root ns lets us rewrite packets
+  # in servo's ovnps namespace to use the provider's DNS resolvers.
+  # a weakness is we can only query 1 NS at a time (unless we were to clone the packets?)
+  # TODO: rework servo's netns to use `firejail`, which is capable of spoofing /etc/resolv.conf.
+  services.resolved.enable = true;  #< to disable, set ` = lib.mkForce false`, as other systemd features default to enabling `resolved`.
+  # without DNSSEC:
+  # - dig matrix.org => works
+  # - curl https://matrix.org => works
+  # with default DNSSEC:
+  # - dig matrix.org => works
+  # - curl https://matrix.org => fails
+  # i don't know why. this might somehow be interfering with the DNS run on this device (trust-dns)
+  services.resolved.dnssec = "false";
+  networking.nameservers = [
+    # use systemd-resolved resolver
+    # full resolver (which understands /etc/hosts) lives on 127.0.0.53
+    # stub resolver (just forwards upstream) lives on 127.0.0.54
+    "127.0.0.53"
+  ];
+
+  # nscd -- the Name Service Caching Daemon -- caches DNS query responses
+  # in a way that's unaware of my VPN routing, so routes are frequently poor against
+  # services which advertise different IPs based on geolocation.
+  # nscd claims to be usable without a cache, but in practice i can't get it to not cache!
+  # nsncd is the Name Service NON-Caching Daemon. it's a drop-in that doesn't cache;
+  # this is OK on the host -- because systemd-resolved caches. it's probably sub-optimal
+  # in the netns and we query upstream DNS more often than needed. hm.
+  # services.nscd.enableNsncd = true;
+
+  # disabling nscd LOSES US SOME FUNCTIONALITY. in particular, only the glibc-builtin modules are accessible via /etc/resolv.conf.
+  # - dns: glibc-bultin
+  # - files: glibc-builtin
+  # - myhostname: systemd
+  # - mymachines: systemd
+  # - resolve: systemd
+  # in practice, i see no difference with nscd disabled.
+  # disabling nscd VASTLY simplifies netns and process isolation. see explainer at top of file.
+  services.nscd.enable = false;
+  system.nssModules = lib.mkForce [];
+}
--- a/hosts/common/net/hostnames.nix
+++ b/hosts/common/net/hostnames.nix
@@ -0,0 +1,15 @@
+{ config, lib, ... }:
+
+{
+  # give each host a shortname that all the other hosts know, to allow easy comms.
+  networking.hosts = lib.mkMerge (builtins.map
+    (host: let
+      cfg = config.sane.hosts.by-name."${host}";
+    in {
+      "${cfg.lan-ip}" = [ host ];
+    } // lib.optionalAttrs (cfg.wg-home.ip != null) {
+      "${cfg.wg-home.ip}" = [ "${host}-hn" ];
+    })
+    (builtins.attrNames config.sane.hosts.by-name)
+  );
+}
--- a/hosts/common/net/upnp.nix
+++ b/hosts/common/net/upnp.nix
@@ -0,0 +1,20 @@
+{ pkgs, ... }:
+{
+  networking.firewall.allowedUDPPorts = [
+    # to receive UPnP advertisements. required by sane-ip-check.
+    # N.B. sane-ip-check isn't query/response based. it needs to receive on port 1900 -- not receive responses FROM port 1900.
+    1900
+  ];
+
+  networking.firewall.extraCommands = with pkgs; ''
+    # after an outgoing SSDP query to the multicast address, open FW for incoming responses.
+    # necessary for anything DLNA, especially go2tv
+    # source: <https://serverfault.com/a/911286>
+    # context: <https://github.com/alexballas/go2tv/issues/72>
+
+    # ipset -! means "don't fail if set already exists"
+    ${ipset}/bin/ipset create -! upnp hash:ip,port timeout 10
+    ${iptables}/bin/iptables -A OUTPUT -d 239.255.255.250/32 -p udp -m udp --dport 1900 -j SET --add-set upnp src,src --exist
+    ${iptables}/bin/iptables -A INPUT -p udp -m set --match-set upnp dst,dst -j ACCEPT
+  '';
+}
--- a/hosts/common/net/vpn.nix
+++ b/hosts/common/net/vpn.nix
@@ -0,0 +1,56 @@
+# to add a new OVPN VPN:
+# - generate a privkey `wg genkey`
+# - add this key to `sops secrets/universal.yaml`
+# - upload pubkey to OVPN.com (`cat wg.priv | wg pubkey`)
+# - generate config @ OVPN.com
+# - copy the Address, PublicKey, Endpoint from OVPN's config
+
+{ config, lib, pkgs, ... }:
+let
+  def-ovpn = name: { endpoint, publicKey, addrV4, id }: {
+    sane.vpn."ovpnd-${name}" = {
+      inherit endpoint publicKey addrV4 id;
+      privateKeyFile = config.sops.secrets."wg/ovpnd_${name}_privkey".path;
+      dns = [
+        "46.227.67.134"
+        "192.165.9.158"
+      ];
+    };
+
+    sops.secrets."wg/ovpnd_${name}_privkey" = {
+      # needs to be readable by systemd-network or else it says "Ignoring network device" and doesn't expose it to networkctl.
+      owner = "systemd-network";
+    };
+  };
+in lib.mkMerge [
+  (def-ovpn "us" {
+    endpoint = "vpn31.prd.losangeles.ovpn.com:9929";
+    publicKey = "VW6bEWMOlOneta1bf6YFE25N/oMGh1E1UFBCfyggd0k=";
+    id = 1;
+    addrV4 = "172.27.237.218";
+    # addrV6 = "fd00:0000:1337:cafe:1111:1111:ab00:4c8f";
+  })
+  # TODO: us-atl disabled until i can give it a different link-local address and wireguard key than us-mi
+  # (def-ovpn "us-atl" {
+  #   endpoint = "vpn18.prd.atlanta.ovpn.com:9929";
+  #   publicKey = "Dpg/4v5s9u0YbrXukfrMpkA+XQqKIFpf8ZFgyw0IkE0=";
+  #   address = [
+  #     "172.21.182.178/32"
+  #     "fd00:0000:1337:cafe:1111:1111:cfcb:27e3/128"
+  #   ];
+  # })
+  (def-ovpn "us-mi" {
+    endpoint = "vpn34.prd.miami.ovpn.com:9929";
+    publicKey = "VtJz2irbu8mdkIQvzlsYhU+k9d55or9mx4A2a14t0V0=";
+    id = 2;
+    addrV4 = "172.21.182.178";
+    # addrV6 = "fd00:0000:1337:cafe:1111:1111:cfcb:27e3";
+  })
+  (def-ovpn "ukr" {
+    endpoint = "vpn96.prd.kyiv.ovpn.com:9929";
+    publicKey = "CjZcXDxaaKpW8b5As1EcNbI6+42A6BjWahwXDCwfVFg=";
+    id = 3;
+    addrV4 = "172.18.180.159";
+    # addrV6 = "fd00:0000:1337:cafe:1111:1111:ec5c:add3";
+  })
+]
--- a/hosts/common/nix-path/default.nix
+++ b/hosts/common/nix-path/default.nix
@@ -1,13 +0,0 @@
-{ pkgs, ... }:
-
-{
-  # allow `nix-shell` (and probably nix-index?) to locate our patched and custom packages
-  nix.nixPath = [
-    "nixpkgs=${pkgs.path}"
-    # note the import starts at repo root: this allows `./overlay/default.nix` to access the stuff at the root
-    # "nixpkgs-overlays=${../../..}/hosts/common/nix-path/overlay"
-    # as long as my system itself doesn't rely on NIXPKGS at runtime, we can point the overlays to git
-    # to avoid switching so much during development
-    "nixpkgs-overlays=/home/colin/dev/nixos/hosts/common/nix-path/overlay"
-  ];
-}
--- a/hosts/common/nix/default.nix
+++ b/hosts/common/nix/default.nix
@@ -0,0 +1,84 @@
+{ config, lib, pkgs, ... }:
+
+{
+  nix.settings = {
+    # see: `man nix.conf`
+
+    # useful when a remote builder has a faster internet connection than me.
+    # note that this also applies to `nix copy --to`, though.
+    # i think any time a remote machine wants a path, this means we ask them to try getting it themselves before we supply it.
+    builders-use-substitutes = true;  # default: false
+
+    # maximum seconds to wait when connecting to binary substituter
+    connect-timeout = 3;  # default: 0
+
+    # download-attempts = 5;  # default: 5
+
+    # allow `nix flake ...` command
+    experimental-features = [ "nix-command" "flakes "];
+
+    # whether to build from source when binary substitution fails
+    fallback = true;  # default: false
+
+    # whether to keep building dependencies if any other one fails
+    keep-going = true;  # default: false
+
+    # whether to keep build-only dependencies of GC roots (e.g. C compiler) when doing GC
+    keep-outputs = true;  # default: false
+
+    # how many lines to show from failed build
+    log-lines = 30;  # default: 10
+
+    # how many substitution downloads to perform in parallel.
+    # i wonder if parallelism is causing moby's substitutions to fail?
+    max-substitution-jobs = 6;  # default: 16
+
+    # narinfo-cache-negative-ttl = 3600  # default: 3600
+    # whether to use ~/.local/state/nix/profile instead of ~/.nix-profile, etc
+    use-xdg-base-directories = true;  # default: false
+
+    # whether to warn if repository has uncommited changes
+    warn-dirty = false;  # default: true
+
+    # hardlinks identical files in the nix store to save 25-35% disk space.
+    # unclear _when_ this occurs. it's not a service.
+    # does the daemon continually scan the nix store?
+    # does the builder use some content-addressed db to efficiently dedupe?
+    auto-optimise-store = true;
+
+    # allow #!nix-shell scripts to locate my patched nixpkgs & custom packages.
+    # this line might become unnecessary: see <https://github.com/NixOS/nixpkgs/pull/273170>
+    nix-path = config.nix.nixPath;
+  };
+
+  # allow `nix-shell` (and probably nix-index?) to locate our patched and custom packages.
+  # this is actually a no-op, and the real action happens in assigning `nix.settings.nix-path`.
+  nix.nixPath = [
+    "nixpkgs=${pkgs.path}"
+    # note the import starts at repo root: this allows `./overlay/default.nix` to access the stuff at the root
+    # "nixpkgs-overlays=${../../..}/hosts/common/nix-path/overlay"
+    # as long as my system itself doesn't rely on NIXPKGS at runtime, we can point the overlays to git
+    # to avoid switching so much during development
+    "nixpkgs-overlays=/home/colin/dev/nixos/hosts/common/nix/overlay"
+  ];
+
+  # ensure new deployments have a source of this repo with which they can bootstrap.
+  environment.etc."nixos".source = ../../..;
+
+  systemd.services.nix-daemon.serviceConfig = {
+    # the nix-daemon manages nix builders
+    # kill nix-daemon subprocesses when systemd-oomd detects an out-of-memory condition
+    # see:
+    # - nixos PR that enabled systemd-oomd: <https://github.com/NixOS/nixpkgs/pull/169613>
+    # - systemd's docs on these properties: <https://www.freedesktop.org/software/systemd/man/systemd.resource-control.html#ManagedOOMSwap=auto%7Ckill>
+    #
+    # systemd's docs warn that without swap, systemd-oomd might not be able to react quick enough to save the system.
+    # see `man oomd.conf` for further tunables that may help.
+    #
+    # alternatively, apply this more broadly with `systemd.oomd.enableSystemSlice = true` or `enableRootSlice`
+    # TODO: also apply this to the guest user's slice (user-1100.slice)
+    # TODO: also apply this to distccd
+    ManagedOOMMemoryPressure = "kill";
+    ManagedOOMSwap = "kill";
+  };
+}
--- a/hosts/common/nix-path/overlay/default.nix
+++ b/hosts/common/nix-path/overlay/default.nix
--- a/hosts/common/persist.nix
+++ b/hosts/common/persist.nix
@@ -1,13 +1,14 @@
 { ... }:

 {
-  sane.persist.stores.private.origin = "/home/colin/private";
-  # store /home/colin/a/b in /home/private/a/b instead of /home/private/home/colin/a/b
+  # store /home/colin/a/b in /mnt/persist/private/a/b instead of /mnt/persist/private/home/colin/a/b
  sane.persist.stores.private.prefix = "/home/colin";

+  sane.persist.sys.byStore.initrd = [
+    "/var/log"
+  ];
  sane.persist.sys.byStore.plaintext = [
    # TODO: these should be private.. somehow
-    "/var/log"
    "/var/backup"  # for e.g. postgres dumps
  ];
  sane.persist.sys.byStore.cryptClearOnBoot = [
--- a/hosts/common/polyunfill.nix
+++ b/hosts/common/polyunfill.nix
@@ -0,0 +1,45 @@
+# strictly *decrease* the scope of the default nixos installation/config
+
+{ lib, ... }:
+{
+  # disable non-required packages like nano, perl, rsync, strace
+  environment.defaultPackages = [];
+
+  # remove all the non-existent default directories from XDG_DATA_DIRS, XDG_CONFIG_DIRS to simplify debugging.
+  # this is defaulted in <repo:nixos/nixpkgs:nixos/modules/programs/environment.nix>,
+  # without being gated by any higher config.
+  environment.profiles = lib.mkForce [
+    "/etc/profiles/per-user/$USER"
+    "/run/current-system/sw"
+  ];
+
+  # NIXPKGS_CONFIG defaults to "/etc/nix/nixpkgs-config.nix", for idfk why.
+  # that's never existed on my system and everything does fine without it set empty (no nixpkgs API to forcibly *unset* it).
+  environment.variables.NIXPKGS_CONFIG = lib.mkForce "";
+  # XDG_CONFIG_DIRS defaults to "/etc/xdg", which doesn't exist.
+  # in practice, pam appends the values i want to XDG_CONFIG_DIRS, though this approach causes an extra leading `:`
+  environment.sessionVariables.XDG_CONFIG_DIRS = lib.mkForce [];
+  # XCURSOR_PATH: defaults to `[ "$HOME/.icons" "$HOME/.local/share/icons" ]`, neither of which i use, just adding noise.
+  # see: <repo:nixos/nixpkgs:nixos/modules/config/xdg/icons.nix>
+  environment.sessionVariables.XCURSOR_PATH = lib.mkForce [];
+
+  # disable nixos' portal module, otherwise /share/applications gets linked into the system and complicates things (sandboxing).
+  # instead, i manage portals myself via the sane.programs API (e.g. sane.programs.xdg-desktop-portal).
+  xdg.portal.enable = false;
+  xdg.menus.enable = false;  #< links /share/applications, and a bunch of other empty (i.e. unused) dirs
+
+  # xdg.autostart.enable defaults to true, and links /etc/xdg/autostart into the environment, populated with .desktop files.
+  # see: <repo:nixos/nixpkgs:nixos/modules/config/xdg/autostart.nix>
+  # .desktop files are a questionable way to autostart things: i generally prefer a service manager for that.
+  xdg.autostart.enable = false;
+
+  # nix.channel.enable: populates `/nix/var/nix/profiles/per-user/root/channels`, `/root/.nix-channels`, `$HOME/.nix-defexpr/channels`
+  #   <repo:nixos/nixpkgs:nixos/modules/config/nix-channel.nix>
+  # TODO: may want to recreate NIX_PATH, nix.settings.nix-path
+  nix.channel.enable = false;
+
+  # environment.stub-ld: populate /lib/ld-linux.so with an object that unconditionally errors on launch,
+  # so as to inform when trying to run a non-nixos binary?
+  # IMO that's confusing: i thought /lib/ld-linux.so was some file actually required by nix.
+  environment.stub-ld.enable = false;
+}
--- a/hosts/common/programs/abaddon.nix
+++ b/hosts/common/programs/abaddon.nix
@@ -0,0 +1,99 @@
+# discord gtk3 client
+{ config, lib, pkgs, ... }:
+let
+  cfg = config.sane.programs.abaddon;
+in
+{
+  sane.programs.abaddon = {
+    configOption = with lib; mkOption {
+      default = {};
+      type = types.submodule {
+        options.autostart = mkOption {
+          type = types.bool;
+          default = false;
+        };
+      };
+    };
+
+    packageUnwrapped = pkgs.abaddon.overrideAttrs (upstream: {
+      patches = (upstream.patches or []) ++ [
+        (pkgs.fetchpatch {
+          url = "https://git.uninsane.org/colin/abaddon/commit/eb551f188d34679f75adcbc83cb8d5beb4d19fd6.patch";
+          name = ''"view members" default to false'';
+          hash = "sha256-9BX8iO86CU1lNrKS1G2BjDR+3IlV9bmhRNTsLrxChwQ=";
+        })
+      ];
+    });
+
+    suggestedPrograms = [ "gnome-keyring" ];
+
+    fs.".config/abaddon/abaddon.ini".symlink.text = ''
+      # see abaddon README.md for options.
+      # at time of writing:
+      # | Setting       | Type    | Default | Description                                                                                      |
+      # |[discord]------|---------|---------|--------------------------------------------------------------------------------------------------|
+      # | `gateway`     | string  |         | override url for Discord gateway. must be json format and use zlib stream compression            |
+      # | `api_base`    | string  |         | override base url for Discord API                                                                |
+      # | `memory_db`   | boolean | false   | if true, Discord data will be kept in memory as opposed to on disk                               |
+      # | `token`       | string  |         | Discord token used to login, this can be set from the menu                                       |
+      # | `prefetch`    | boolean | false   | if true, new messages will cause the avatar and image attachments to be automatically downloaded |
+      # | `autoconnect` | boolean | false   | autoconnect to discord                                                                           |
+      # |[http]--------|--------|---------|---------------------------------------------------------------------------------------------|
+      # | `user_agent` | string |         | sets the user-agent to use in HTTP requests to the Discord API (not including media/images) |
+      # | `concurrent` | int    | 20      | how many images can be concurrently retrieved                                               |
+      # |[gui}------------------------|---------|---------|----------------------------------------------------------------------------------------------------------------------------|
+      # | `member_list_discriminator` | boolean | true    | show user discriminators in the member list                                                                                |
+      # | `stock_emojis`              | boolean | true    | allow abaddon to substitute unicode emojis with images from emojis.bin, must be false to allow GTK to render emojis itself |
+      # | `custom_emojis`             | boolean | true    | download and use custom Discord emojis                                                                                     |
+      # | `css`                       | string  |         | path to the main CSS file                                                                                                  |
+      # | `animations`                | boolean | true    | use animated images where available (e.g. server icons, emojis, avatars). false means static images will be used           |
+      # | `animated_guild_hover_only` | boolean | true    | only animate guild icons when the guild is being hovered over                                                              |
+      # | `owner_crown`               | boolean | true    | show a crown next to the owner                                                                                             |
+      # | `unreads`                   | boolean | true    | show unread indicators and mention badges                                                                                  |
+      # | `save_state`                | boolean | true    | save the state of the gui (active channels, tabs, expanded channels)                                                       |
+      # | `alt_menu`                  | boolean | false   | keep the menu hidden unless revealed with alt key                                                                          |
+      # | `hide_to_tray`              | boolean | false   | hide abaddon to the system tray on window close                                                                            |
+      # | `show_deleted_indicator`    | boolean | true    | show \[deleted\] indicator next to deleted messages instead of actually deleting the message                               |
+      # | `font_scale`                | double  |         | scale font rendering. 1 is unchanged                                                                                       |
+      # |[style]------------------|--------|-----------------------------------------------------|
+      # | `linkcolor`             | string | color to use for links in messages                  |
+      # | `expandercolor`         | string | color to use for the expander in the channel list   |
+      # | `nsfwchannelcolor`      | string | color to use for NSFW channels in the channel list  |
+      # | `channelcolor`          | string | color to use for SFW channels in the channel list   |
+      # | `mentionbadgecolor`     | string | background color for mention badges                 |
+      # | `mentionbadgetextcolor` | string | color to use for number displayed on mention badges |
+      # | `unreadcolor`           | string | color to use for the unread indicator               |
+      # |[notifications]|---------|--------------------------|-------------------------------------------------------------------------------|
+      # | `enabled`     | boolean | true (if not on Windows) | Enable desktop notifications                                                  |
+      # | `playsound`   | boolean | true                     | Enable notification sounds. Requires ENABLE_NOTIFICATION_SOUNDS=TRUE in CMake |
+      # |[voice]--|--------|------------------------------------|------------------------------------------------------------|
+      # | `vad`   | string | rnnoise if enabled, gate otherwise | Method used for voice activity detection. Changeable in UI |
+      # |[windows]|---------|---------|-------------------------|
+      # | `hideconsole` | boolean | true    | Hide console on startup |
+
+      # N.B.: abaddon writes this file itself (and even when i don't change anything internally).
+      # it prefers no spaces around the equal sign.
+      [discord]
+      autoconnect=true
+
+      [notifications]
+      # playsound: i manage sounds via swaync
+      playsound=false
+    '';
+
+    persist.byStore.private = [
+      ".cache/abaddon"
+    ];
+
+    services.abaddon = {
+      description = "unofficial Discord chat client";
+      wantedBy = lib.mkIf cfg.config.autostart [ "graphical-session.target" ];
+      serviceConfig = {
+        ExecStart = "${cfg.package}/bin/abaddon";
+        Type = "simple";
+        Restart = "always";
+        RestartSec = "20s";
+      };
+    };
+  };
+}
--- a/hosts/common/programs/aerc.nix
+++ b/hosts/common/programs/aerc.nix
@@ -3,6 +3,9 @@

 {
  sane.programs.aerc = {
+    sandbox.method = "bwrap";
+    sandbox.wrapperType = "inplace";
+    sandbox.net = "clearnet";
    secrets.".config/aerc/accounts.conf" = ../../../secrets/common/aerc_accounts.conf.bin;
    mime.associations."x-scheme-handler/mailto" = "aerc.desktop";
  };
--- a/hosts/common/programs/alacritty.nix
+++ b/hosts/common/programs/alacritty.nix
@@ -6,19 +6,36 @@
 { lib, ... }:
 {
  sane.programs.alacritty = {
+    sandbox.enable = false;
    env.TERMINAL = lib.mkDefault "alacritty";
-    # note: alacritty will switch to .toml config in 13.0 release
-    # - run `alacritty migrate` to convert the yaml to toml
-    fs.".config/alacritty/alacritty.yml".symlink.text = ''
-      font:
-        size: 14
+    fs.".config/alacritty/alacritty.toml".symlink.text = ''
+      [font]
+      size = 14

-      key_bindings:
-        - { key: N,         mods: Control,        action: CreateNewWindow }
-        - { key: PageUp,    mods: Control,        action: ScrollPageUp }
-        - { key: PageDown,  mods: Control,        action: ScrollPageDown }
-        - { key: PageUp,    mods: Control|Shift,  action: ScrollPageUp }
-        - { key: PageDown,  mods: Control|Shift,  action: ScrollPageDown }
+      [[keyboard.bindings]]
+      mods = "Control"
+      key = "N"
+      action = "CreateNewWindow"
+
+      [[keyboard.bindings]]
+      mods = "Control"
+      key = "PageUp"
+      action = "ScrollPageUp"
+
+      [[keyboard.bindings]]
+      mods = "Control"
+      key = "PageDown"
+      action = "ScrollPageDown"
+
+      [[keyboard.bindings]]
+      mods = "Control|Shift"
+      key = "PageUp"
+      action = "ScrollPageUp"
+
+      [[keyboard.bindings]]
+      mods = "Control|Shift"
+      key = "PageDown"
+      action = "ScrollPageDown"
    '';
  };
 }
--- a/hosts/common/programs/animatch.nix
+++ b/hosts/common/programs/animatch.nix
@@ -0,0 +1,42 @@
+# debug with:
+# - `animatch --debug`
+# - `gdb animatch`
+# try:
+# - `animatch --fullscreen`
+# - `animatch --windowed`
+# the other config options (e.g. verbose logging -- which doesn't seem to do anything) have to be configured via .ini file
+# ```ini
+# # ~/.config/Holy Pangolin/Animatch/SuperDerpy.ini
+# [SuperDerpy]
+# debug=1
+# disableTouch=1
+# [game]
+# verbose=1
+# ```
+{ pkgs, ... }:
+{
+  sane.programs.animatch = {
+    packageUnwrapped = with pkgs; animatch.override {
+      # allegro has no native wayland support, and so by default crashes when run without Xwayland.
+      # enable the allegro SDL backend, and achieve Wayland support via SDL's Wayland support.
+      # TODO: see about upstreaming this to nixpkgs?
+      allegro5 = allegro5.overrideAttrs (upstream: {
+        buildInputs = upstream.buildInputs ++ [
+          SDL2
+        ];
+        cmakeFlags = upstream.cmakeFlags ++ [
+          "-DALLEGRO_SDL=on"
+        ];
+      });
+    };
+
+    sandbox.method = "bwrap";
+    sandbox.wrapperType = "wrappedDerivation";
+    sandbox.whitelistWayland = true;
+
+    persist.byStore.plaintext = [
+      # ".config/Holy Pangolin/Animatch"  #< used for SuperDerpy config (e.g. debug, disableTouch, fullscreen, enable sound, etc). SuperDerpy.ini
+      ".local/share/Holy Pangolin/Animatch"  #< used for game state (level clears). SuperDerpy.ini
+    ];
+  };
+}
--- a/hosts/common/programs/assorted.nix
+++ b/hosts/common/programs/assorted.nix
--- a/hosts/common/programs/audacity.nix
+++ b/hosts/common/programs/audacity.nix
@@ -0,0 +1,35 @@
+{ pkgs, ... }:
+{
+  sane.programs.audacity = {
+    packageUnwrapped = pkgs.audacity.override {
+      # wxGTK32 uses webkitgtk-4.0.
+      # audacity doesn't actually need webkit though, so diable to reduce closure
+      wxGTK32 = pkgs.wxGTK32.override {
+        withWebKit = false;
+      };
+    };
+
+    sandbox.method = "bwrap";
+    sandbox.wrapperType = "wrappedDerivation";
+    sandbox.whitelistAudio = true;
+    sandbox.whitelistWayland = true;
+    sandbox.autodetectCliPaths = true;
+    sandbox.extraHomePaths = [
+      # support media imports via file->open dir to some common media directories
+      "tmp"
+      "Music"
+      # audacity needs the entire config dir mounted if running in a sandbox
+      ".config/audacity"
+    ];
+
+    # disable first-run splash screen
+    fs.".config/audacity/audacity.cfg".file.text = ''
+      PrefsVersion=1.1.1r1
+      [GUI]
+      ShowSplashScreen=0
+      [Version]
+      Major=3
+      Minor=4
+    '';
+  };
+}
--- a/hosts/common/programs/bemenu.nix
+++ b/hosts/common/programs/bemenu.nix
@@ -87,7 +87,14 @@ let
 in
 {
  sane.programs.bemenu = {
-    package = pkgs.bemenu.overrideAttrs (upstream: {
+    sandbox.method = "bwrap";  # landlock works, but requires *all* of /run/user/$ID to be granted.
+    sandbox.wrapperType = "wrappedDerivation";
+    sandbox.whitelistWayland = true;
+    sandbox.extraHomePaths = [
+      ".cache/fontconfig"  #< else it complains, and is *way* slower
+    ];
+
+    packageUnwrapped = pkgs.bemenu.overrideAttrs (upstream: {
      nativeBuildInputs = (upstream.nativeBuildInputs or []) ++ [
        pkgs.makeWrapper
      ];
--- a/hosts/common/programs/bonsai.nix
+++ b/hosts/common/programs/bonsai.nix
@@ -0,0 +1,130 @@
+# bonsai docs: <https://sr.ht/~stacyharper/bonsai/>
+{ config, lib, pkgs, ... }:
+let
+  cfg = config.sane.programs.bonsai;
+
+  delayType = with lib; types.submodule {
+    options = {
+      type = mkOption {
+        type = types.enum [ "delay" ];
+        # default = "delay";
+      };
+      delay_duration = mkOption {
+        type = types.int;
+        description = ''
+          used for "delay" types only.
+          nanoseconds until the event is finalized.
+        '';
+      };
+      transitions = mkOption {
+        type = types.listOf transitionType;
+        default = [];
+        description = ''
+          list of transitions out of this state (i.e. after completing the delay).
+        '';
+      };
+    };
+  };
+  eventType = with lib; types.submodule {
+    options = {
+      type = mkOption {
+        type = types.enum [ "event" ];
+        # default = "event";
+      };
+      event_name = mkOption {
+        type = types.str;
+        description = ''
+          name of event which this transition applies to.
+        '';
+      };
+      transitions = mkOption {
+        type = types.listOf transitionType;
+        default = [];
+        description = ''
+          list of transitions out of this state.
+        '';
+      };
+    };
+  };
+  execType = with lib; types.submodule {
+    options = {
+      type = mkOption {
+        type = types.enum [ "exec" ];
+        # default = "exec";
+      };
+      command = mkOption {
+        type = types.listOf types.str;
+        description = ''
+          command to run when the event is triggered.
+        '';
+      };
+      transitions = mkOption {
+        type = types.listOf transitionType;
+        default = [];
+        description = ''
+          list of transitions out of this state (i.e. after successfully executing the command)
+        '';
+      };
+    };
+  };
+  isDelay = x: delayType.check x && x.type == "delay";
+  isEvent = x: eventType.check x && x.type == "event";
+  isExec = x: execType.check x && x.type == "exec";
+  # unfortunately, `types.oneOf` is naive about submodules, so we need our own type.
+  #   transitionType = lib.types.oneOf [ delayType eventType execType ];
+  transitionType = with lib.types; mkOptionType {
+    name = "transition";
+    check = x: isDelay x || isEvent x || isExec x;
+    merge = loc: defs: let
+      defList = builtins.map (d: d.value) defs;
+    in
+      if builtins.all isDelay defList then
+        delayType.merge loc defs
+      else if builtins.all isEvent defList then
+        eventType.merge loc defs
+      else if builtins.all isExec defList then
+        execType.merge loc defs
+      else
+        mergeOneOption loc defs
+    ;
+  };
+in
+{
+  sane.programs.bonsai = {
+    configOption = with lib; mkOption {
+      default = {};
+      type = types.submodule {
+        options = {
+          transitions = mkOption {
+            type = types.listOf transitionType;
+            default = [];
+          };
+          configFile = mkOption {
+            type = types.path;
+            default = pkgs.writeText "bonsai_tree.json" (builtins.toJSON cfg.config.transitions);
+            description = ''
+              configuration file to pass to bonsai.
+              usually auto-generated from the sibling options; exposed mainly for debugging or convenience.
+            '';
+          };
+        };
+      };
+    };
+
+    services.bonsaid = {
+      description = "bonsai: programmable input dispatcher";
+      after = [ "graphical-session.target" ];
+      wantedBy = [ "graphical-session.target" ];
+
+      script = ''
+        ${pkgs.coreutils}/bin/rm -f $XDG_RUNTIME_DIR/bonsai
+        exec ${cfg.package}/bin/bonsaid -t ${cfg.config.configFile}
+      '';
+      serviceConfig = {
+        Type = "simple";
+        Restart = "always";
+        RestartSec = "5s";
+      };
+    };
+  };
+}
--- a/hosts/common/programs/brave.nix
+++ b/hosts/common/programs/brave.nix
@@ -1,6 +1,17 @@
 { ... }:
 {
  sane.programs.brave = {
+    sandbox.method = "bwrap";
+    sandbox.wrapperType = "inplace";  # /opt/share/brave.com vendor-style packaging
+    sandbox.net = "all";
+    sandbox.extraHomePaths = [
+      "dev"  # for developing anything web-related
+      "tmp"
+    ];
+    sandbox.whitelistAudio = true;
+    sandbox.whitelistDri = true;
+    sandbox.whitelistWayland = true;
+
    persist.byStore.cryptClearOnBoot = [
      ".cache/BraveSoftware"
      ".config/BraveSoftware"
--- a/hosts/common/programs/bubblewrap.nix
+++ b/hosts/common/programs/bubblewrap.nix
@@ -0,0 +1,35 @@
+{ pkgs, ... }:
+{
+  sane.programs.bubblewrap = {
+    sandbox.enable = false;  # don't sandbox the sandboxer :)
+    packageUnwrapped = pkgs.bubblewrap.overrideAttrs (base: {
+      # patches = (base.patches or []) ++ [
+      #   (pkgs.fetchpatch {
+      #     url = "https://git.uninsane.org/colin/bubblewrap/commit/9843f9b2b5f086563fd37250658d69350a2939be.patch";
+      #     name = "enable debug logging and add a bunch more tracing";
+      #     hash = "sha256-AlDsqddaBahhqGibZlCjgmChuK7mmxDt0aYHNgY05OI=";
+      #   })
+      # ];
+      postPatch = (base.postPatch or "") + ''
+        # bwrap doesn't like to be invoked with any capabilities, which is troublesome if i
+        # want to do things like ship CAP_NET_ADMIN,CAP_NET_RAW in the ambient set for tools like Wireshark.
+        # but this limitation of bwrap is artificial and at first look is just a scenario the author probably
+        # never expected: patch out the guard check.
+        #
+        # see: <https://github.com/containers/bubblewrap/issues/397>
+        #
+        # note that invoking bwrap with capabilities in the 'init' namespace does NOT grant the sandboxed process
+        # capabilities in the 'init' namespace. it's a limitation of namespaces that namespaced processes can
+        # never receive capabilities in their parent namespace.
+        substituteInPlace bubblewrap.c --replace \
+          'die ("Unexpected capabilities but not setuid, old file caps config?");' \
+          '// die ("Unexpected capabilities but not setuid, old file caps config?");'
+
+        # enable debug printing
+        # substituteInPlace utils.h --replace \
+        #   '#define __debug__(x)' \
+        #   '#define __debug__(x) printf x'
+      '';
+    });
+  };
+}
--- a/hosts/common/programs/calls.nix
+++ b/hosts/common/programs/calls.nix
@@ -44,7 +44,7 @@ in
    services.gnome-calls = {
      # TODO: prevent gnome-calls from daemonizing when started manually
      description = "gnome-calls daemon to monitor incoming SIP calls";
-      wantedBy = lib.mkIf cfg.config.autostart [ "default.target" ];
+      wantedBy = lib.mkIf cfg.config.autostart [ "graphical-session.target" ];
      serviceConfig = {
        # add --verbose for more debugging
        ExecStart = "${cfg.package}/bin/gnome-calls --daemon";
--- a/hosts/common/programs/catt.nix
+++ b/hosts/common/programs/catt.nix
@@ -0,0 +1,29 @@
+# use like:
+# - catt -d lgtv_chrome cast ./path/to.mp4
+#
+# support matrix:
+# - webm: audio only
+# - mp4: audio + video
+{ config, lib, ... }:
+let
+  cfg = config.sane.programs.catt;
+in
+{
+  sane.programs.catt = {
+    fs.".config/catt/catt.cfg".symlink.text = ''
+      [options]
+      device = lgtv_chrome
+
+      [aliases]
+      lgtv_chrome = 10.78.79.106
+    '';
+  };
+
+  # necessary to cast local files
+  networking.firewall.allowedTCPPortRanges = lib.mkIf cfg.enabled [
+    {
+      from = 45000;
+      to = 47000;
+    }
+  ];
+}
--- a/hosts/common/programs/chatty.nix
+++ b/hosts/common/programs/chatty.nix
@@ -1,40 +1,8 @@
 { pkgs, ... }:
-let
-  chattyNoOauth = pkgs.chatty.override {
-    # the OAuth feature (presumably used for web-based logins) pulls a full webkitgtk.
-    # especially when using the gtk3 version of evolution-data-server, it's an ancient webkitgtk_4_1.
-    # disable OAuth for a faster build & smaller closure
-    evolution-data-server = pkgs.evolution-data-server.override {
-      enableOAuth2 = false;
-      gnome-online-accounts = pkgs.gnome-online-accounts.override {
-        # disables the upstream "goabackend" feature -- presumably "Gnome Online Accounts Backend"
-        # frees us from webkit_4_1, in turn.
-        enableBackend = false;
-        gvfs = pkgs.gvfs.override {
-          # saves 20 minutes of build time, for unused feature
-          samba = null;
-        };
-      };
-    };
-  };
-  chatty-latest = pkgs.chatty-latest.override {
-    evolution-data-server-gtk4 = pkgs.evolution-data-server-gtk4.override {
-      gnome-online-accounts = pkgs.gnome-online-accounts.override {
-        # disables the upstream "goabackend" feature -- presumably "Gnome Online Accounts Backend"
-        # frees us from webkit_4_1, in turn.
-        enableBackend = false;
-        gvfs = pkgs.gvfs.override {
-          # saves 20 minutes of build time and cross issues, for unused feature
-          samba = null;
-        };
-      };
-    };
-  };
-in
 {
  sane.programs.chatty = {
-    # package = chattyNoOauth;
-    package = chatty-latest;
+    # packageUnwrapped = chattyNoOauth;
+    packageUnwrapped = pkgs.chatty-latest;
    suggestedPrograms = [ "gnome-keyring" ];
    persist.byStore.private = [
      ".local/share/chatty"  # matrix avatars and files
--- a/hosts/common/programs/conky/battery_estimate
+++ b/hosts/common/programs/conky/battery_estimate
@@ -1,32 +1,184 @@
+#!/bin/sh
 #!/usr/bin/env nix-shell
 #!nix-shell -i bash

-full=$(cat /sys/class/power_supply/axp20x-battery/charge_full_design)
-rate=$(cat /sys/class/power_supply/axp20x-battery/current_now)
-perc=$(cat /sys/class/power_supply/axp20x-battery/capacity)
-perc_left=$((100 - $perc))
-# these icons come from sxmo; they only render in nerdfonts
-bat_dis="󱊢"
-bat_chg="󱊥"
+usage() {
+  echo "usage: battery_estimate [options...]"
+  echo
+  echo "pretty-prints a battery estimate (icon to indicate state, and a duration estimate)"
+  echo
+  echo "options:"
+  echo "  --debug: output additional information, to stderr"
+  echo "  --minute-suffix <string>:  use the provided string as a minutes suffix"
+  echo "  --hour-suffix <string>:  use the provided string as an hours suffix"
+  echo "  --icon-suffix <string>:  use the provided string as an icon suffix"
+  echo "  --percent-suffix <string>:  use the provided string when displaying percents"
+}

-fmt_minutes() {
-  # args: <battery symbol> <text if ludicrous estimate> <estimated minutes to full/empty>
-  if [[ $3 -gt 1440 ]]; then
-    printf "%s %s" "$1" "$2"  # more than 1d
-  else
-    hr=$(($3 / 60))
-    hr_in_min=$(($hr * 60))
-    min=$(($3 - $hr_in_min))
-    printf "%s %dh%02dm" "$1" "$hr" "$min"
+# these icons come from sxmo; they only render in nerdfonts
+icon_bat_chg=("󰢟" "󱊤" "󱊥" "󰂅")
+icon_bat_dis=("󰂎" "󱊡" "󱊢" "󱊣")
+suffix_icon=" "  # thin space
+suffix_percent="%"
+# suffix_icon=" "
+
+# render time like: 2ʰ08ᵐ
+# unicode sub/super-scripts: <https://en.wikipedia.org/wiki/Unicode_subscripts_and_superscripts>
+# symbol_hr="ʰ"
+# symbol_min="ᵐ"
+
+# render time like: 2ₕ08ₘ
+# symbol_hr="ₕ"
+# symbol_min="ₘ"
+
+# render time like: 2h08m
+# symbol_hr="h"
+# symbol_min="m"
+
+# render time like: 2:08
+# symbol_hr=":"
+# symbol_min=
+
+# render time like: 2꞉08⧗
+symbol_hr="꞉"
+symbol_min="⧗"
+# variants:
+# symbol_hr=":"
+# symbol_min="⧖"
+# symbol_min="⌛"
+
+# render time like: 2'08"
+# symbol_hr="'"
+# symbol_min='"'
+
+log() {
+  if [ "$BATTERY_ESTIMATE_DEBUG" = "1" ]; then
+    printf "$@" >&2
+    echo >&2
  fi
 }

-if [[ $rate -lt 0 ]]; then
-  # discharging
-  fmt_minutes "$bat_dis" '∞' "$(($full * 60 * $perc / (-100 * $rate)))"
-elif [[ $rate -gt 0 ]]; then
-  # charging
-  fmt_minutes "$bat_chg" '100%' "$(($full * 60 * $perc_left / (100 * $rate)))"
-else
-  echo "$bat_dis $perc%"
+render_icon() {
+  # args:
+  # 1: "chg" or "dis"
+  # 2: current battery percentage
+  level=$(($2 / 25))
+  level=$(($level > 3 ? 3 : $level))
+  level=$(($level < 0 ? 0 : $level))
+  log "icon: %s %d" "$1" "$level"
+  if [ "$1" = "dis" ]; then
+    printf "%s" "${icon_bat_dis[$level]}"
+  elif [ "$1" = "chg" ]; then
+    printf "%s" "${icon_bat_chg[$level]}"
  fi
+}
+
+try_path() {
+  # assigns output variables:
+  # - perc, perc_from_full  (0-100)
+  # - full, rate (pos means charging)
+  if [ -f "$1/capacity" ]; then
+    log "perc, perc_from_full from %s" "$1/capacity"
+    perc=$(cat "$1/capacity")
+    perc_from_full=$((100 - $perc))
+  fi
+
+  if [ -f "$1/charge_full_design" ] && [ -f "$1/current_now" ]; then
+    log "full, rate from %s and %s" "$1/charge_full_design" "$1/current_now"
+    # current is positive when charging
+    full=$(cat "$1/charge_full_design")
+    rate=$(cat "$1/current_now")
+  elif [ -f "$1/energy_full" ] && [ -f "$1/power_now" ]; then
+    log "full, rate from %s and %s" "$1/energy_full" "$1/power_now"
+    # power_now is positive when discharging
+    full=$(cat "$1/energy_full")
+    rate=-$(cat "$1/power_now")
+  elif [ -f "$1/energy_full" ] && [ -f "$1/energy_now" ]; then
+    log "full, rate from %s and %s" "$1/energy_full" "$1/energy_now"
+    log "  this is a compatibility path for legacy Thinkpad batteries which do not populate the 'power_now' field, and incorrectly populate 'energy_now' with power info"
+    # energy_now is positive when discharging
+    full=$(cat "$1/energy_full")
+    rate=-$(cat "$1/energy_now")
+  fi
+}
+
+try_all_paths() {
+  try_path "/sys/class/power_supply/axp20x-battery"  # Pinephone
+  try_path "/sys/class/power_supply/BAT0"  # Thinkpad
+  log "perc: %d, perc_from_full: %d" "$perc" "$perc_from_full"
+  log "full: %f, rate: %f" "$full" "$rate"
+  log "  rate > 0 means charging, else discharging"
+}
+
+fmt_minutes() {
+  # args:
+  # 1: icon to render
+  # 2: string to show if charge/discharge time is indefinite
+  # 3: minutes to stable state (i.e. to full charge or full discharge)
+  #    - we work in minutes instead of hours for precision: bash math is integer-only
+  log "charge/discharge time: %f min" "$3"
+  # args: <battery symbol> <text if ludicrous estimate> <estimated minutes to full/empty>
+  if [ -n "$3" ] && [ "$3" -lt 1440 ]; then
+    hr=$(($3 / 60))
+    hr_in_min=$(($hr * 60))
+    min=$(($3 - $hr_in_min))
+    printf "%s%s%d%s%02d%s" "$1" "$suffix_icon" "$hr" "$symbol_hr" "$min" "$symbol_min"
+  else
+    log "charge/discharge duration > 1d"
+    printf "%s%s%s" "$1" "$suffix_icon" "$2"  # more than 1d
+  fi
+}
+
+pretty_output() {
+  if [ -n "$perc" ]; then
+    duration=""
+    if [ "$rate" -gt 0 ]; then
+      log "charging"
+      icon="$(render_icon chg $perc)"
+      duration="$(($full * 60 * $perc_from_full / (100 * $rate)))"
+    else
+      log "discharging"
+      icon="$(render_icon dis $perc)"
+      if [ "$rate" -lt 0 ]; then
+        duration="$(($full * 60 * $perc / (-100 * $rate)))"
+      fi
+    fi
+    fmt_minutes "$icon" "$perc$suffix_percent" "$duration"
+  fi
+}
+
+while [ "$#" -gt 0 ]; do
+  case "$1" in
+    "--debug")
+      shift
+      BATTERY_ESTIMATE_DEBUG=1
+      ;;
+    "--icon-suffix")
+      shift
+      suffix_icon="$1"
+      shift
+      ;;
+    "--hour-suffix")
+      shift
+      symbol_hr="$1"
+      shift
+      ;;
+    "--minute-suffix")
+      shift
+      symbol_min="$1"
+      shift
+      ;;
+    "--percent-suffix")
+      shift
+      suffix_percent="$1"
+      shift
+      ;;
+    *)
+      usage
+      exit 1
+      ;;
+  esac
+done
+
+try_all_paths
+pretty_output
--- a/hosts/common/programs/conky/conky.conf
+++ b/hosts/common/programs/conky/conky.conf
@@ -3,6 +3,11 @@
 -- - can also use #rrggbb syntax
 -- example configs: <https://forum.manjaro.org/t/conky-showcase-2022/97123>
 -- example configs: <https://www.reddit.com/r/Conkyporn/>
+--
+-- exec options:
+-- `exec <cmd>` => executes the command, synchronously, renders its output as text
+-- `texeci <interval_sec> <cmd>` => executes the command periodically, async (to not block render), renders as text
+-- `pexec <cmd>` => executes the command, synchronously, parses its output

 conky.config = {
  out_to_wayland = true,
@@ -35,16 +40,43 @@ conky.config = {
  color2 = '404040',
 }

-- texeci <interval_sec> <cmd>: run the command periodically, _in a separate thread_ so as not to block rendering
+vars = {
+  -- kBps = 'K/s',
+  kBps = 'ᴷᐟˢ',
+  -- percent = '%',
+  -- percent = '﹪',
+  percent = '٪',
+  -- percent = '⁒',
+  -- percent = '％',
+  icon_suffix = nil,
+  hour_suffix = nil,
+  minute_suffix = '${font sans-serif:size=14}${color2}⧗',
+}
+
+bat_args = ""
+if vars.icon_suffix ~= nil then
+  bat_args = bat_args .. " --icon-suffix '" .. vars.icon_suffix .. "'"
+end
+if vars.hour_suffix ~= nil then
+  bat_args = bat_args .. " --hour-suffix '" .. vars.hour_suffix .. "'"
+end
+if vars.minute_suffix ~= nil then
+  bat_args = bat_args .. " --minute-suffix '" .. vars.minute_suffix .. "'"
+end
+if vars.percent ~= nil then
+  bat_args = bat_args .. " --percent-suffix '" .. vars.percent .. "'"
+end
+
+-- N.B.: `[[ <text> ]]` is Lua's multiline string literal
 conky.text = [[
 ${color1}${shadecolor 707070}${font sans-serif:size=50:style=Bold}${alignc}${exec date +"%H:%M"}${font}
 ${color2}${shadecolor a4d7d0}${font sans-serif:size=20}${alignc}${exec date +"%a %d %b"}${font}


-${color1}${shadecolor}${font sans-serif:size=22:style=Bold}${alignc}${exec @bat@ }${font}
+${color1}${shadecolor}${font sans-serif:size=22:style=Bold}${alignc}${execp @bat@ ]] .. bat_args .. [[ }${font}
 ${color1}${shadecolor}${font sans-serif:size=20:style=Bold}${alignc}${texeci 600 @weather@ }${font}


-${color2}${shadecolor a4d7d0}${font sans-serif:size=16}${alignc}⇅ ${downspeedf wlan0}K/s${font}
-${font sans-serif:size=16}${alignc}☵ $memperc%  $cpu%${font}
+${color2}${shadecolor a4d7d0}${font sans-serif:size=16}${alignc}⇅ ${downspeedf wlan0}]] .. vars.kBps .. [[${font}
+${font sans-serif:size=16}${alignc}☵ $memperc]] .. vars.percent .. [[  $cpu]] .. vars.percent .. [[${font}
 ]]
--- a/hosts/common/programs/conky/default.nix
+++ b/hosts/common/programs/conky/default.nix
@@ -1,11 +1,22 @@
 { config, pkgs, ... }:
 {
  sane.programs.conky = {
+    # TODO: non-sandboxed `conky` still ships via `sxmo-utils`, but unused
+    sandbox.method = "bwrap";
+    sandbox.net = "clearnet";  #< for the scripts it calls (weather)
+    sandbox.extraPaths = [
+      "/sys/class/power_supply"
+      "/sys/devices"  # needed by battery_estimate
+      # "/sys/devices/cpu"
+      # "/sys/devices/system"
+    ];
+    sandbox.whitelistWayland = true;
+
    fs.".config/conky/conky.conf".symlink.target =
      let
        battery_estimate = pkgs.static-nix-shell.mkBash {
          pname = "battery_estimate";
-          src = ./.;
+          srcRoot = ./.;
        };
      in pkgs.substituteAll {
        src = ./conky.conf;
@@ -15,20 +26,14 @@

    services.conky = {
      description = "conky dynamic desktop background";
-      wantedBy = [ "default.target" ];
-      # XXX: should be part of graphical-session.target, but whatever mix of greetd/sway
-      # i'm using means that target's never reached...
-      # wantedBy = [ "graphical-session.target" ];
-      # partOf = [ "graphical-session.target" ];
+      after = [ "graphical-session.target" ];
+      # partOf = [ "graphical-session.target" ];  # propagate stop/restart signal from graphical-session to this unit
+      wantedBy = [ "graphical-session.target" ];

      serviceConfig.ExecStart = "${config.sane.programs.conky.package}/bin/conky";
      serviceConfig.Type = "simple";
      serviceConfig.Restart = "on-failure";
      serviceConfig.RestartSec = "10s";
-      # serviceConfig.Slice = "session.slice";
-
-      # don't start conky until after sway
-      preStart = ''test -n "$SWAYSOCK"'';
    };
  };
 }
--- a/hosts/common/programs/cozy.nix
+++ b/hosts/common/programs/cozy.nix
@@ -2,6 +2,16 @@

 {
  sane.programs.cozy = {
+    sandbox.method = "bwrap";  # landlock gives: _multiprocessing.SemLock: Permission Denied
+    sandbox.wrapperType = "wrappedDerivation";
+    sandbox.whitelistAudio = true;
+    sandbox.whitelistDbus = [ "user" ];  # mpris
+    sandbox.whitelistWayland = true;
+    sandbox.extraHomePaths = [
+      "Books/local"
+      "Books/servo"
+    ];
+
    # cozy uses a sqlite db for its config and exposes no CLI options other than --help and --debug
    persist.byStore.plaintext = [
      ".local/share/cozy"  # sqlite db (config & index?)
--- a/hosts/common/programs/dconf.nix
+++ b/hosts/common/programs/dconf.nix
@@ -0,0 +1,33 @@
+# dconf docs: <https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/desktop_migration_and_administration_guide/profiles>
+# this lets programs temporarily write user-level dconf settings (aka gsettings).
+# they're written to ~/.config/dconf/user, unless `DCONF_PROFILE` is set to something other than the default of /etc/dconf/profile/user
+# find keys/values with `dconf dump /`
+{ config, lib, pkgs, ... }:
+
+let
+  cfg = config.sane.programs.dconf;
+in
+{
+  sane.programs.dconf = {
+    sandbox.method = "bwrap";
+    sandbox.wrapperType = "wrappedDerivation";
+    persist.byStore.private = [
+      ".config/dconf"
+    ];
+  };
+
+  programs.dconf = lib.mkIf cfg.enabled {
+    # note that `programs.dconf` doesn't allow specifying the dconf package.
+    enable = true;
+    packages = [
+      (pkgs.writeTextFile {
+        name = "dconf-user-profile";
+        destination = "/etc/dconf/profile/user";
+        text = ''
+          user-db:user
+          system-db:site
+        '';
+      })
+    ];
+  };
+}
--- a/hosts/common/programs/default.nix
+++ b/hosts/common/programs/default.nix
@@ -2,72 +2,119 @@

 {
  imports = [
+    ./abaddon.nix
    ./aerc.nix
    ./alacritty.nix
+    ./animatch.nix
    ./assorted.nix
+    ./audacity.nix
    ./bemenu.nix
+    ./bonsai.nix
    ./brave.nix
+    ./bubblewrap.nix
    ./calls.nix
    ./cantata.nix
+    ./catt.nix
    ./chatty.nix
    ./conky
    ./cozy.nix
+    ./dconf.nix
+    ./dialect.nix
    ./dino.nix
    ./element-desktop.nix
    ./epiphany.nix
    ./evince.nix
    ./feedbackd.nix
    ./firefox.nix
+    ./firejail.nix
    ./flare-signal.nix
    ./fontconfig.nix
    ./fractal.nix
+    ./frozen-bubble.nix
    ./fwupd.nix
    ./g4music.nix
    ./gajim.nix
+    ./gdbus.nix
    ./geary.nix
    ./git.nix
    ./gnome-feeds.nix
-    ./gnome-keyring.nix
+    ./gnome-keyring
+    ./gnome-maps.nix
    ./gnome-weather.nix
+    ./go2tv.nix
    ./gpodder.nix
+    ./grimshot.nix
    ./gthumb.nix
+    ./gtkcord4.nix
+    ./handbrake.nix
    ./helix.nix
    ./imagemagick.nix
    ./jellyfin-media-player.nix
+    ./kdenlive.nix
    ./komikku.nix
    ./koreader
    ./libreoffice.nix
    ./lemoa.nix
+    ./loupe.nix
    ./mako.nix
    ./megapixels.nix
    ./mepo.nix
+    ./mimeo
    ./mopidy.nix
    ./mpv.nix
    ./msmtp.nix
+    ./nautilus.nix
    ./neovim.nix
    ./newsflash.nix
    ./nheko.nix
+    ./nicotine-plus.nix
    ./nix-index.nix
+    ./notejot.nix
    ./ntfy-sh.nix
    ./obsidian.nix
    ./offlineimap.nix
+    ./open-in-mpv.nix
+    ./pipewire.nix
+    ./planify.nix
+    ./portfolio-filemanager.nix
    ./playerctl.nix
    ./rhythmbox.nix
    ./ripgrep.nix
+    ./rofi
+    ./sane-scripts.nix
    ./sfeed.nix
+    ./signal-desktop.nix
    ./splatmoji.nix
+    ./spot.nix
    ./spotify.nix
    ./steam.nix
    ./stepmania.nix
+    ./strings.nix
    ./sublime-music.nix
+    ./supertuxkart.nix
+    ./sway
+    ./sway-autoscaler
+    ./swaylock.nix
    ./swaynotificationcenter.nix
    ./tangram.nix
-    ./tor-browser-bundle-bin.nix
+    ./tor-browser.nix
    ./tuba.nix
+    ./unl0kr
    ./vlc.nix
+    ./waybar
+    ./waylock.nix
+    ./wike.nix
+    ./wine.nix
+    ./wireplumber.nix
    ./wireshark.nix
+    ./wob
    ./xarchiver.nix
+    ./xdg-desktop-portal.nix
+    ./xdg-desktop-portal-gtk.nix
+    ./xdg-desktop-portal-wlr.nix
+    ./xdg-utils.nix
    ./zeal.nix
+    ./zecwallet-lite.nix
    ./zsh
  ];

--- a/hosts/common/programs/dialect.nix
+++ b/hosts/common/programs/dialect.nix
@@ -0,0 +1,19 @@
+{ pkgs, ... }:
+{
+  sane.programs.dialect = {
+    sandbox.method = "bwrap";
+    sandbox.wrapperType = "inplace";  # share/search_providers/ calls back into the binary, weird wrap semantics
+    sandbox.whitelistWayland = true;
+    sandbox.net = "clearnet";
+    suggestedPrograms = [ "dconf" ];  #< to persist settings
+
+    packageUnwrapped = pkgs.dialect.overrideAttrs (upstream: {
+      # TODO: send upstream
+      # TODO: figure out how to get audio working
+      # TODO: move to runtimeDependencies?
+      buildInputs = upstream.buildInputs ++ [
+        pkgs.glib-networking  # for TLS
+      ];
+    });
+  };
+}
--- a/hosts/common/programs/dino.nix
+++ b/hosts/common/programs/dino.nix
@@ -40,16 +40,39 @@ in
      type = types.submodule {
        options.autostart = mkOption {
          type = types.bool;
-          default = false;
+          default = true;
        };
      };
    };

+    sandbox.method = "bwrap";
+    sandbox.wrapperType = "wrappedDerivation";
+    sandbox.net = "clearnet";
+    sandbox.whitelistAudio = true;
+    sandbox.whitelistDbus = [ "user" ];  # notifications
+    sandbox.whitelistDri = true;  #< not strictly necessary, but we need all the perf we can get on moby
+    sandbox.whitelistWayland = true;
+    sandbox.extraHomePaths = [
+      "Music"
+      "Pictures/albums"
+      "Pictures/cat"
+      "Pictures/from"
+      "Pictures/Photos"
+      "Pictures/Screenshots"
+      "Pictures/servo-macros"
+      "Videos/local"
+      "Videos/servo"
+      "tmp"
+    ];
+
    persist.byStore.private = [ ".local/share/dino" ];

    services.dino = {
-      description = "auto-start and maintain dino XMPP connection";
-      wantedBy = lib.mkIf cfg.config.autostart [ "default.target" ];
+      description = "dino XMPP client";
+      after = [ "graphical-session.target" ];
+      # partOf = [ "graphical-session.target" ];
+      wantedBy = lib.mkIf cfg.config.autostart [ "graphical-session.target" ];
+
      serviceConfig = {
        ExecStart = "${cfg.package}/bin/dino";
        Type = "simple";
--- a/Show More
+++ b/Show More