Add git-based auto-update for Linux deployment

- install.sh now clones from git instead of copying files
- Service runs git pull on restart for automatic updates
- Support config.local.json for production settings (gitignored)
- kao.py prefers config.local.json when present

To update production: push changes, then 'sudo systemctl restart kao'

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

.gitignore

@@ -8,6 +8,7 @@ __pycache__/
 
 # Runtime files
 status.json
+config.local.json
 
 # IDE
 .vscode/