69968f2e8b
Round 6 hit account-level rate throttling the concurrency AIMD cannot absorb: at 26 req/min the gateway still returned 16% 429s and each one burned a third of the retry budget. Retry-After-guided 429s now back off without consuming attempts (gRPC pushback semantics); the retry loop gains a per-call ceiling using the same dual-condition stall verdict as quota-wait (local window exceeded AND no global progress).