Harness 4.2 Local setup and control UI [inspector client] #6551

Part of #6535.

• Add a checklist to the composer notice:
  • pack download progress (local-harness-consent.ts ~736 onProgress)
  • authorization
  • a Git ≥2.31 check for unattended runs (run-resources.ts ~168-176)
• Add Forget and Stop-all buttons. They should call stopAllLocalHarnessSessions (client/src/lib/local-harness-consent.ts ~726) and the hook's revoke (useLocalHarnessTarget.ts ~1068), which currently have no UI callers.

Delivery rules

• Fresh worktree and branch; each PR at most 400 handwritten changed lines; stack when necessary.
• Verify the actual failing boundary and run repository checks.
• Preserve broker-only model auth, no venue/engine fallback, and separate infrastructure failures.
• Human-only: production deployment, flags/env changes, rebuilds/backfills, signed/published packs and large paid runs.

Status: planned; completion requires the acceptance evidence above.

Pull request stack

• MCPJam/inspector#6586: feat(local): show setup readiness and session controls

The implementation hub records merge order, current verification and remaining release gates. PR publication does not mark the deployed or packaged acceptance matrix complete.