Hardened: Logs Land, Versions Bump, the Sidecar Heals Itself

First contact with the desktop client surfaced four ways the orchestrator-as-a-service could go sideways. All four are closed in this pass.

• FastAPI
• Sidecar-Process
• Log-Persistence
• Versioning
• Lifecycle
• Tauri-Framework
• Self-Healing
• Stop-Button
• Pytest