The driver can request_reimage(reason) when its build VM is broken past the usual fixes (before the go-ahead too: it asks, it doesn't act). The harness parks the work in progress (pushed to Gitea), then blocks the VM in the state store (schema 5, vm_blocks): no item on any project on it is taken up, across restarts. The operator hears once at top level, with the command to clear it, and each blocked item's thread gets a line. `vm ready <project>` lifts the block and trusts the VM's new host key; a reimaged VM is set up again by the toolchain step, and the item that found it goes first. loop.qnt gains the block (blocked_vm_runs_nothing) and a scenario; it found that a reimage lost work in progress, hence parking first. The walk requests reimages and recovers them, reimaged or not. The unreachable case reuses the block in #137. Architecture P5 is softer, and D3 describes the block. Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01J5Utyfzw7gF7UhjRDEtjTk