Settings page gains two new sections:
- Connected Accounts: shows linked Google email (read-only)
- Gemini API Key: paste personal key from aistudio.google.com,
shows masked hint of saved key, remove link to revert to server key
POST /settings/gemini-key saves/clears gemini_api_key in auth.json.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>