- POST /settings/ai/test sends a minimal text prompt to verify the provider
- Returns ok/message — maps HTTP status codes to human-readable explanations
- 405 → "URL pointing at wrong place, check custom URL has no path suffix"
- 401 → invalid key, 404 → wrong path, 429 → rate limited, etc.
- Test button appears once a key is saved; result shown inline below buttons
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
