refactor: wrap ScheduleExecutor handleMissedRun in transaction

[dean0x]

Summary

ScheduleExecutor.handleMissedRun() performs two separate database operations without transaction protection. If the first succeeds but the second fails, the schedule is cancelled with no audit trail.

Affected Code

File: src/services/schedule-executor.ts (lines 385-415)

Two sequential operations:

1. scheduleRepo.update() — cancels the schedule
2. scheduleRepo.recordExecution() — records the failed execution audit trail

If step 1 succeeds but step 2 fails, the schedule is cancelled with no audit record explaining why.

Proposed Fix

Inject Database into ScheduleExecutor (same pattern used in ScheduleHandler from #81) and wrap both calls in database.runInTransaction() using the sync variants (updateSync, recordExecutionSync).

Risk

Low — both operations target the same entity type and the audit trail gap is cosmetic.

References

• Identified during Issue refactor: add runInTransaction for atomic multi-step DB operations #81 planning (transaction atomicity refactor)
• runInTransaction infrastructure added in refactor: add runInTransaction for atomic multi-step DB operations #81