Live per-member status of one pool (breaker/concurrency/latency)

The LIVE per-pool detail read (GET /api/v1/admin/pools/{name}), the reliability/capacity dashboard data: each member's breaker state, concurrency headroom, in-flight count, latency EWMA, and success/error tallies, read from the SAME store signals the routing seam ranks on. No LLM content, no credentials.