feat: implement Phase 4 enhancements

- Migrate frontend to Alpine.js for reactive state management
- Add source health dashboard in UI and /api/source-health endpoint
- Add event tagging (PATCH /api/events/{id}/tags) and commenting (POST /api/events/{id}/comments)
- Add CSV/JSON export from the UI
- Add rule-based alerting engine (rules.py) with CRUD endpoints (/api/rules)
- Add SIEM export via webhook (siem.py)
- Add AOC audit trail middleware logging all mutations to aoc_audit collection
- Update config with SIEM_ENABLED, SIEM_WEBHOOK_URL, ALERTS_ENABLED
- Add tests for rules engine, tags, comments, and source health

pyproject.toml

@@ -4,7 +4,7 @@ line-length = 120
 
 [tool.ruff.lint]
 select = ["E", "F", "I", "N", "W", "UP", "B", "C4", "SIM"]
-ignore = ["E501"]
+ignore = ["E501", "B008"]
 
 [tool.ruff.lint.pydocstyle]
 convention = "google"