- Add "Sign in with SSO" button on login page (shown when OIDC is configured)
- Add /oidc/callback route to exchange authorization code for JWT tokens
- Add loginWithOidcCode action to auth store
- Treat issuer URI as complete discovery URL (no auto-append of .well-known)
- Update admin page placeholder to show full discovery URL format
- Fix datetime picker calendar icon visibility in dark mode (color-scheme)
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
