## Summary
- **Ping checks never scheduled**: `ensure_default_ping_check` created check records but never called `schedule_check`, so auto-created ping checks never executed
- **Skipped checks permanently orphaned**: `CheckExecutorWorker` only rescheduled checks that actually executed — skipped checks (agent-assigned, SNMP disabled) broke the scheduling chain permanently
- **No recovery mechanism**: `JobHealthCheckWorker` only recovered `DeviceMonitorWorker` jobs, not `CheckExecutorWorker` jobs — any lost check job was gone forever
## Changes
- `monitoring.ex`: Call `schedule_check` after creating ping check in `ensure_default_ping_check`
- `check_executor_worker.ex`: Reschedule skipped-but-enabled checks so conditions are re-evaluated next cycle
- `job_health_check_worker.ex`: Recover orphaned `CheckExecutorWorker` jobs for enabled checks (runs every 10 min)
- `devices.ex`: Wrap `ensure_default_ping_check` in try/rescue for deadlock resilience
## Test plan
- [x] New tests: ping check scheduling on creation, no duplicate scheduling on idempotent call
- [x] Updated tests: skipped checks now assert rescheduling instead of orphaning
- [x] New tests: health check worker recovers orphaned check executor jobs, skips disabled checks
- [x] All 177 targeted tests pass
- [x] Compile clean with warnings-as-errors
- [x] Pre-commit hooks pass (credo, format)
Reviewed-on: graham/towerops-web#71