argus: add active alerting system (Phase 1)
Three new files for the engineering acceleration initiative:
- alerting.py: 7 health check functions (dormant agents, quality regression,
throughput anomaly, rejection spikes, stuck loops, cost spikes, domain
rejection patterns) + failure report generator
- alerting_routes.py: /check, /api/alerts, /api/failure-report/{agent} endpoints
- PATCH_INSTRUCTIONS.md: integration guide for app.py (imports, route
registration, auth middleware bypass, DB connection)
Observe and alert only — no pipeline modification. Independence constraint
is load-bearing for measurement trustworthiness.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
m3taversal
33e670b436