Rates Engine v0.5.0-rc.68

[v0.5.0-rc.68] — 2026-05-22

Fixed

• SLA probe false-failed on /v1/issuers availability (#54).
  ratesengine-sla-probe's worker loop recorded every hit()
  result unconditionally — including the one request per worker
  still in flight when the run-duration context expired. That
  cancelled request was counted as a 2xx miss, so every run
  reported exactly concurrency phantom failures (~0.3% loss),
  over-attributed to the slowest endpoint (/v1/issuers, ~81ms —
  the widest window to be in flight when the deadline lands). It
  was tripping ratesengine_sla_probe_unit_failed (P3) with no
  real breach: the API served 100% (server logs + 2,400 manual
  requests confirm), latency/freshness passed comfortably. Fix:
  discard samples whose request was cancelled by the run-duration
  ctx (the probe aborting itself ≠ a server failure); a genuine
  mid-window failure still counts. Also gave the probe a cloned
  transport with MaxIdleConnsPerHost = concurrency*2 so the
  single-host workload reuses keep-alive connections instead of
  churning the default pool of 2.