6017b4a117
Document the per-target egressProxy.hostNetwork YAML option and the real-deps-500m production-ready throughput acceptance profile in docs/reference/platform-infra.md, and add a single-active guard to the k3s-build-benchmark start path so a new run deletes any prior target+profile Job before applying the new one (preventing concurrent runs from making status report the wrong Job, observed during #1077 regression on D518). Basis: merges PR #1065 (real k3s dependency proxy benchmark + hostNetwork egress proxy) as the production-ready scaffold; validated on D601 and D518 with real-deps-500m (both succeeded, apk=1231/npm=850/go=693/real_deps=2774 MiB, proxyserver cumulative 2.4 GiB / 10 GiB).