Prevents users from having to re-authorize Astrolabe after periods of
inactivity by proactively refreshing OAuth tokens before they expire.
Changes:
- Add RefreshUserTokens background job that runs every 15 minutes
- Add on-demand token refresh in SemanticSearchProvider (Unified Search)
- Store issued_at timestamp for accurate token lifetime calculation
- Add getAllUsersWithTokens() to query users needing refresh
The job dynamically calculates refresh threshold based on actual token
lifetime (50% remaining), working with any IdP (Nextcloud OIDC, Keycloak,
etc.) rather than relying on IdP-specific configuration.
Closes#510
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Chris Coutinho