alpaca: ship on moby; fix cross

hosts/common/programs/alpaca.nix

@@ -1,14 +1,36 @@
 # alpaca: ollama llm client
 # - super simple, easy UI
+#
+# shortcomings (as of 6.1.7, 2025-07-23):
 # - doesn't seem to do any prompt tuning;
 #   inherits all the pathologies of the underlying model (e.g. makes up citations)
 #
 # it creates a config dir, `~/.config/com.jeffser.Alpaca`, but apparently empty
 #
 # TODO: configure ollama connection details statically
-{ ... }:
+# TODO: update the nix package 6.1.7 -> 7.5.2
+# - i.e. review <https://github.com/NixOS/nixpkgs/pull/420698>
+{ pkgs, ... }:
 {
   sane.programs.alpaca = {
+    packageUnwrapped = (pkgs.alpaca.override {
+      # ollama is only added to `PATH`; since i'm using it via http, remove it here.
+      # fixes cross compilation & simplifies closure.
+      ollama = null;
+      python3Packages = pkgs.python3Packages // {
+        # XXX(2025-07-23): does not cross compile (markitdown -> pydub -> ... -> opencv)
+        markitdown = null;
+      };
+    }).overrideAttrs (upstream: {
+      postPatch = (upstream.postPatch or "") + ''
+        # for nulled dependencies (above), patch so the application only errors
+        # at runtime, on first attempted use.
+        substituteInPlace src/widgets/attachments.py \
+          --replace-fail 'from markitdown' '# from markitdown'
+      '';
+    });
+    buildCost = 2;  #< liable to break cross during updates; not important enough to block deploy over
+
     sandbox.net = "all";  # maybe only needs wireguard, actually
     sandbox.whitelistWayland = true;
     sandbox.mesaCacheDir = ".cache/com.jeffser.Alpaca/mesa";

hosts/common/programs/assorted.nix

@@ -303,6 +303,7 @@ in
     guiBaseApps = declPackageSet [
       # "abaddon"  # discord client
       "alacritty"  # terminal emulator
+      "alpaca"  # ollama/LLM client
       "blanket"  # ambient noise generator
       "calls"  # gnome calls (dialer/handler)
       "confy"  # conference planning app
@@ -402,7 +403,6 @@ in
       "pcGameApps"
       "pcTuiApps"
       ####
-      "alpaca"  # ollama/LLM client
       "audacity"
       "brave"  # for the integrated wallet -- as a backup
       # "cantata"  # music player (mpd frontend)