Trim verbose comments to concise, self-contained notes

Cut restated "what", domain-glossary framing, cross-file consumption
narration, and against-alternative justification from in-file comments;
keep only non-obvious "why" and load-bearing pointers. Drop the
`generateCompletions` line (a no-op restatement of the upstream default)
and its comment.

modules/claude-code/claude-code.nix

@@ -3,19 +3,14 @@
   lib,
   ...
 }:
-# Claude Code — Anthropic's CLI — for the primary user, configured declaratively
-# through home-manager. home-manager ships the package and manages ~/.claude:
-# the global agent instructions (./CLAUDE.md), the skills tree (./skills), the
-# attention-bell hook (./hooks), and settings.json (the model and the hook
-# wiring). Login credentials are left unmanaged so they survive rebuilds;
-# signing in without a browser, as needed over the console or SSH, is covered in
-# ./authentication.md.
+# Claude Code for the primary user, configured through home-manager, which ships
+# the package and manages ~/.claude. Login credentials are left unmanaged so they
+# survive rebuilds.
 let
   cfg = config.modules.claude-code;
   user = config.user.name;
 
-  # Rings the terminal bell so tmux flags the background pane; wired to both the
-  # end of a turn and attention notifications below.
+  # Rings the terminal bell so tmux flags the background pane.
   bellHook = [
     {
       hooks = [
@@ -37,12 +32,10 @@ in
       # Global agent instructions, rendered to ~/.claude/CLAUDE.md.
       context = ./CLAUDE.md;
 
-      # One directory per skill, each carrying its SKILL.md, symlinked under
-      # ~/.claude/skills.
+      # One directory per skill, symlinked under ~/.claude/skills.
       skills = ./skills;
 
-      # Installed executable at ~/.claude/hooks/attention-bell.sh, where the
-      # settings hooks reference it.
+      # Installed at ~/.claude/hooks/attention-bell.sh, referenced by the settings below.
       hooks."attention-bell.sh" = builtins.readFile ./hooks/attention-bell.sh;
 
       settings = {