test(installer): add OpenSSH distro harness

docs/README.md

@@ -28,7 +28,7 @@ disagree, update both in the same change or mark the discrepancy explicitly.
 | [network-diagnostics.md](network-diagnostics.md) | Confirmation checks and dedicated diagnostic tasks | Partial |
 | [critical-check-cluster.md](critical-check-cluster.md) | Raft-backed dispatchless critical checks | Scaffold only |
 | [public-endpoint-and-identity.md](public-endpoint-and-identity.md) | One HTTPS origin, peer status, CA/mTLS, managed Raft topology | Planned; peer HTTPS partial |
-| [source-installation.md](source-installation.md) | Go SSH source installer and Docker/OpenSSH test matrix | Planned |
+| [source-installation.md](source-installation.md) | Go SSH source installer and Docker/OpenSSH test matrix | Partial: harness + planning landed, remote build pending |
 | [implementation-roadmap.md](implementation-roadmap.md) | Ordered repository work packages and release gates | Active |
 | [source-plan-migration.md](source-plan-migration.md) | Source-to-target conversion ledger and resolved conflicts | Complete mapping |