docs: condense comments across the repo

Comments had drifted into multi-paragraph narrative (git commit
lineage, debugging stories, restated code) in several hot spots
(scripts/deploy, hermes-agent.nix, flake.nix, gitea.nix, headscale.nix).
Trim every comment to its load-bearing "why" — gotchas, safety
warnings, and non-obvious rationale survive verbatim in substance,
just tightened to 1-2 sentences; historical narrative and anything
already covered in CLAUDE.md is cut. No code/logic changed.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UJqEmY1y3AYX3JoX4Y6b21

pkgs/tome.nix

@@ -56,13 +56,11 @@ buildDotnetModule (finalAttrs: {
 
   executables = [ "Tome.App" ];
 
-  # wrapGAppsHook3: buildDotnetModule sets dontWrapGApps = true by default (to
-  # avoid double-wrapping) but its own wrap step still splices gappsWrapperArgs
-  # in when the hook is present (see nixpkgs' libation package, same pattern).
-  # Without it the binary never gets XDG_DATA_DIRS/GSETTINGS_SCHEMA_DIR set, so
-  # GTK/WebKitGTK can't find the icon theme or GTK settings from the desktop
-  # session — symptoms: missing icons and a denser default UI font/size than
-  # when launched from an already-fully-initialized session (e.g. via Rider).
+  # buildDotnetModule sets dontWrapGApps = true by default, but wrapGAppsHook3's
+  # own wrap step still splices gappsWrapperArgs in when present (same pattern
+  # as nixpkgs' libation). Without it XDG_DATA_DIRS/GSETTINGS_SCHEMA_DIR never
+  # get set, so GTK/WebKitGTK can't find the icon theme or settings — missing
+  # icons, denser default UI font.
   nativeBuildInputs = [ copyDesktopItems wrapGAppsHook3 ];
 
   runtimeDeps = [