Get Metrics Summary

Get key metrics summary for dashboard. Story 4.2 AC6: Key metrics exposed: call volume, latency p50/p95/p99, error rates. Note: This endpoint fetches metrics from Prometheus and aggregates them. In production, consider caching these values in Redis for performance. Returns: MetricsSummary with aggregated metrics

curl -X GET "https://loading/api/v1/monitoring/metrics"

{
  "call_volume_24h": 0,
  "concurrent_calls": 0,
  "e2e_latency": {
    "p50_ms": 0,
    "p95_ms": 0,
    "p99_ms": 0
  },
  "error_rate_percent": 0,
  "llm_latency": {
    "p50_ms": 0,
    "p95_ms": 0,
    "p99_ms": 0
  },
  "mcp_latency": {
    "p50_ms": 0,
    "p95_ms": 0,
    "p99_ms": 0
  },
  "timestamp": "string"
}