CI: Tier C regression test script (automated)

[renecannao]

Automated Regression Tests

Codify all Tier C regression tests into a reproducible script.

Tests (from manual session)

Chi Router v1 API Regression

• GET /api/clusters → 200
• GET /api/cluster-info/{alias} → 200
• GET /api/problems → 200
• GET /api/audit-recovery → 200
• GET /api/maintenance → 200

API v2 Validation

• GET /api/v2/clusters → 200, has "status" field
• GET /api/v2/status → 200
• GET /api/v2/recoveries → 200
• GET /api/v2/proxysql/servers → 200
• GET /api/v2/instances/nonexistent/9999 → 404

Prometheus Metrics

• GET /metrics → 200
• Contains orchestrator_instances_total
• Contains orchestrator_clusters_total
• Contains orchestrator_discoveries_total

Health Endpoints

• GET /health/live → 200
• GET /health/ready → 200
• GET /health/leader → 200

Web UI & Static Files

• GET / → 302
• GET /css/orchestrator.css → 200
• GET /js/orchestrator.js → 200

Files

• tests/functional/test-regression.sh

Acceptance criteria

• 22+ tests, all passing
• Script exits 0/non-zero appropriately

Depends on #46 (infrastructure).