programs: add (and ship) see-cat; a program to pretty-print anything in the terminal

hosts/common/programs/assorted.nix

@@ -106,6 +106,7 @@ in
       "rsync"
       # "s6-rc"  # service manager
       # "screen"
+      "see-cat"  # pretty-print equivalent to 'cat'
       "smartmontools"  # smartctl
       # "socat"
       "strace"

hosts/common/programs/default.nix

@@ -176,6 +176,7 @@
     ./sblast
     ./schlock.nix
     ./seatd.nix
+    ./see-cat.nix
     ./sfeed.nix
     ./shadow.nix
     ./signal-desktop.nix

hosts/common/programs/see-cat.nix

@@ -0,0 +1,8 @@
+{ ... }:
+{
+  sane.programs.see-cat = {
+    # if image rendering is enabled, "existing" may be too restrictive;
+    # grant access to the whole directory, as images are usually somewhere within that.
+    sandbox.autodetectCliPaths = "existingDirOrParent";
+  };
+}