- proxy.go: extract applyWarmup + acquireScheduledBackend to reduce ServeHTTP complexity - proxy_test.go: TestProxyQueueFull, TestProxyCacheHitLogging (AC5/AC6/AC7 HTTP-level coverage) - scheduler_test.go: TestBackendAcquireCancelledContext + runtime.Gosched spin-wait (no time.Sleep) - router_test.go: TestAuthenticate_MethodCapabilityOverrideDirect with real RS256 JWT + JWKS server