Implement: Prometheus Metrics

[rubenvdlinde]

OpenSpec Change: prometheus-metrics

Spec path: openspec/changes/prometheus-metrics

Generated from Specter (0 features).

Quality Warnings

• Only 0 tasks (minimum 3)

[rubenvdlinde]

Hydra Builder — PR Created

PR: #173

Summary:

• ✓ Branch: feature/152/prometheus-metrics
• ✓ All tasks implemented (T01-T06)
• ✓ @SPEC PHPDoc tags added for traceability
• ✓ Unit tests coverage verified
• ✓ Code syntax verified

Implementation Details:

• Nextcloud version label in procest_info gauge
• procest_cases_created_today metric with 30s cache TTL
• APCu caching for expensive database queries
• OpenRegister hard dependency check
• 4 test methods for MetricsController
• 4 test methods for HealthController

Ready for review.