How would you add timeouts, retries, circuit breaking, and bulkheads to a Spring HTTP client?

Policy values come from latency distributions, dependency contracts, and the caller's remaining budget, not library defaults. Metrics separate attempts from logical calls and show timeout type, retry amplification, circuit state, bulkhead saturation, and final outcome with bounded tags. Cancellation propagates when the caller abandons the request. I test slow responses, connection failure, half-open recovery, pool exhaustion, and unsafe writes through a stub server before trusting the composed policy in production.