fix: stop native Windows hydrate runners

[steipete]

Summary

• Remove the stale native-Windows guard from the Actions hydrate stop-marker path.
• Keep the existing safety checks: only write when the lease id and SSH target are known.
• Add regression coverage so native Windows hydrated runners are treated as stop-marker capable.

Verification

• go test ./internal/cli -run 'Test(ActionsHydrationStopIsWrittenForNativeWindowsTargets|WindowsActionsHydrationMarkerCommandsUsePowerShellHome|RemoteWriteActionsHydrationStopMatchesWorkflowInput|RemoteClearActionsHydrationStateRemovesReadyAndStop)$'
• git diff --check
• /Users/steipete/Projects/agent-scripts/skills/autoreview/scripts/autoreview --mode branch --base origin/main

[clawsweeper]

ClawSweeper status: review started.

I am starting a fresh review of this pull request: fix: stop native Windows hydrate runners This is item 1/1 in the current shard. Shard 0/1.

This placeholder means the worker is alive and reading the current context. I will edit this same comment with the actual review when the claws are done clicking.

Crustacean status: shell secured, claws on keyboard, evidence pebbles being sorted.