- Add Alarm model with tenant/part/machine relationships and 3 indexes
- Add alembic migration c5d6e7f8a9b0_add_alarms
- Add alarms API: list (filter by ack/severity), summary, acknowledge
- Auto-generate alarms on counter update (threshold warning, critical at 100%)
- Duplicate alarm prevention for same part+alarm_type
- Add alarms frontend page with active/acknowledged tabs, summary badges
- 9 new tests (67/67 total passing)
Co-Authored-By: Claude Opus 4 <noreply@anthropic.com>
