feat(desktop): Electron shell M2 — embedded server, desktop login, instance lock (#173)

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

pnpm-workspace.yaml

@@ -13,3 +13,6 @@ allowBuilds:
   "@google/genai": true
   esbuild: true
   protobufjs: true
+  # electron's postinstall downloads the platform runtime binary; without this allow
+  # entry pnpm skips it and `electron .` has nothing to launch.
+  electron: true