feat: integrate Electron for desktop app

- Add electron-vite + Electron Forge tooling
- Create Electron main process with embedded Express server
- Create preload script with native dialog IPC bridge
- Refactor server.ts to export createExpressApp() (dual web/electron)
- Adapt renderQueue.ts for packaged binaries + pre-built bundle
- Add ensureBrowser() for Chrome Headless Shell pre-download
- Add scripts/bundle-remotion.js for packaging
- Data persists in ~/Library/Application Support/Bradly/
- Web mode preserved via npm run dev:web

.gitignore

@@ -4,6 +4,7 @@ node_modules/
 # Build output
 build/
 dist/
+out/
 *.cjs
 *.cjs.map