Scheduled connector sync (cron)

[RobertLD]

Problem

Connector syncs must be triggered manually via CLI or API. There is no built-in way to schedule periodic syncs, forcing users to set up external cron jobs or scheduled tasks.

Implementation Plan

1. Add schedule config to connector configuration:

   {
     "connectors": {
       "notion": {
         "schedule": "0 */6 * * *"
       }
     }
   }

2. Install node-cron (or similar lightweight cron library) as a dependency
3. Background scheduler: Create src/core/scheduler.ts:
   • startScheduler(config) — reads connector configs, registers cron jobs
   • Each job triggers the corresponding connector sync
   • Logs next-run time for each scheduled connector
   • Graceful shutdown: stop all jobs on SIGTERM/SIGINT
4. Integrate with libscope serve: Start the scheduler when the API server starts
5. Health check enhancement: Include next-run times in GET /api/v1/health response
6. CLI visibility: Show schedule info in libscope connectors status

Files to Modify

• package.json — add node-cron dependency
• src/core/scheduler.ts — new file with scheduler logic
• src/api/server.ts — start scheduler on serve
• src/api/routes.ts — add schedule info to health endpoint
• src/config.ts — add schedule field to connector config type

Testing Strategy

• Unit test: cron expression parsing and validation
• Unit test: scheduler registers and fires jobs (mock clock)
• Unit test: graceful shutdown stops all jobs
• Integration test: configure a short interval, verify sync triggers
• Test invalid cron expressions → clear error at startup