Resolve PLAN.md conflict by keeping both plans: Provider management
system and Scheduled Tasks enhancement.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Implement a full Provider management layer compatible with Claude Code's settings.json protocol.
- ProviderService: CRUD + activation + settings.json sync + HTTP connectivity test
- Provider REST API: 8 endpoints (list, get, create, update, delete, activate, test)
- API key masking in GET responses (sk-a****xyz)
- Models API refactored to read from active Provider dynamically
- 42 unit tests + 6 real-config integration tests, all passing
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>