chore: ignore local Claude Code settings

.claude/settings.local.json was only excluded by a machine-global
ignore file, so it would be trackable in any fresh clone. It holds
machine-local state (including the internal Gitea host), so ignore
it from the repo itself. Also cover the .tmp.* files written during
atomic saves, which otherwise break `git add -A`.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

.gitignore

@@ -39,4 +39,7 @@ google_cred/
 *.safetensors
 # os cruft
 .DS_Store
-Thumbs.db
+Thumbs.db
+# editor / agent local state
+.claude/settings.local.json
+.claude/settings.local.json.tmp.*