Tune legacy proxy circuit breaker and cache

Goal: adjust circuit breaker and caching behavior for legacy proxy.

Config: ServiceConfigs/BFF/config/legacy_services.yaml

• circuit_breaker.threshold, circuit_breaker.reset_time
• response_cache.enabled, default_ttl, max_size
• legacy_service_timeouts.{service}

Procedure

1. Update the YAML values above and promote per SOP
2. Validate with traffic; monitor Prometheus:
   • circuit_breaker_status{service="..."}
   • circuit_breaks_total{service="..."}
   • cache_hits_total, cache_misses_total

Notes

• Non‑GET writes invalidate cache for affected paths automatically
• 413 indicates request body exceeds request_limits.max_body_size

See also: ../reference/legacy-proxy, ./alerting-cookbook