chore(deps): update indigo to v0.0.0-20260202 and simplify OAuth scopes
Update bluesky-social/indigo dependency to the latest version and adapt
to its API changes. Also simplify OAuth configuration by removing the
deprecated transition:generic scope.
Changes:
- Update Go version from 1.24.0 to 1.25
- Update indigo to v0.0.0-20260202181658-ea3d39eec464
- Fix DID parsing calls to use value type instead of pointer (indigo API change)
- Remove transition:generic from OAuth scopes (now using atproto only)
- Fix test isolation in CleanupExpiredSessions test
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>