8878711cf3
- GATEWAY_MAX_BODY_BYTES (1 MiB): connect WithReadMaxBytes + http.MaxBytesReader
on the public mux; explicit http2.Server MaxConcurrentStreams/IdleTimeout and
an http.Server ReadHeaderTimeout (R2 report follow-up).
- gateway_rate_limited_total{class} counter, Debug per rejection, a rejection
tracker drained every 30 s into a Warn summary per key and a report POST to
/api/v1/internal/ratelimit/report (feeds the admin view + auto-flag).
- The dead AdminPerMinute/AdminBurst policy now guards the /_gm mount (429),
ahead of its Basic-Auth.
- resolve() logs the cause of infra session-resolve failures at Warn (the
transient unauthenticated dips from the R2 run); unknown tokens stay silent.