[Epic] Monitoring

[2witstudios]

Overview

Observability improvements for monitoring infrastructure reliability and data quality.

Tasks

• [Monitoring] Session ID preservation #538 - Preserve sessionId/requestId in middleware-flushed api_metrics (complete)
• [Monitoring] Key validation #539 - Prevent silent monitoring degradation when MONITORING_INGEST_KEY is missing (complete)
• [Monitoring] Retention policy #540 - Define and enforce configurable retention policy for system_logs and api_metrics
• [Monitoring] Ingest hardening #543 - Harden monitoring ingest (closed — false positive, query params already stripped by sanitizer)

Acceptance Criteria

• Session/request IDs preserved in metrics
• Monitoring failures are loud (not silent)
• Retention policies configurable per data class and enforced with expiresAt

Notes

P3 observability. Most tasks complete. Remaining work is #540 (retention policy governance).