fix(gastown): regenerate statusline optimization patch with correct line numbers

The patch file had malformed hunk headers with incorrect line numbers
and counts, causing it to fail to apply against the locked gastown rev
(177094a2). This was NOT a flake.lock issue - gastown source was properly
locked.

Changes:
- Regenerated patch from scratch against locked gastown revision
- Re-enabled the patch in default.nix (was commented out with TODO)
- Updated comment to accurately describe the optimization

The optimization skips expensive beads queries for detached tmux sessions
and caches status line output with a 10-second TTL, reducing Dolt CPU
usage from ~70% to ~20%.

Closes: hq-0h1p9m

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

home/roles/development/default.nix

@@ -55,9 +55,9 @@ let
       ./gastown-fix-town-root-detection.patch
       # Fix copyDir to handle symlinks (broken symlinks cause "no such file" errors)
       ./gastown-fix-copydir-symlinks.patch
-      # TODO: Statusline optimization patch needs regenerating against current gastown source
-      # Reduces Dolt CPU from ~70% to ~20% by avoiding beads queries for sessions nobody is watching
-      # ./gastown-statusline-optimization.patch
+      # Statusline optimization: skip expensive beads queries for detached sessions
+      # Reduces Dolt CPU from ~70% to ~20% by caching and early-exit
+      ./gastown-statusline-optimization.patch
     ];
 
     meta = with lib; {