feat: add Electron hot-reload development mode

- Add electron-dev.mjs script for hot-reload development
- Support automatic Electron dependency building
- Start Remix dev server and Electron app concurrently
- Add proper process management and cleanup
- Fix preload script path for development mode
- Add electron:dev and electron:dev:inspect npm scripts

This enables developers to run 'pnpm electron:dev' for a complete
hot-reload development experience with automatic rebuilding and
process management.

package.json

@@ -30,6 +30,8 @@
     "preview": "pnpm run build && pnpm run start",
     "prepare": "husky",
     "clean": "node scripts/clean.js",
+    "electron:dev": "node scripts/electron-dev.mjs",
+    "electron:dev:inspect": "NODE_ENV=development electron --inspect=9229 build/electron/main/index.mjs",
     "electron:build:deps": "concurrently \"pnpm electron:build:main\" \"pnpm electron:build:preload\" --kill-others-on-fail",
     "electron:build:main": "vite build --config ./electron/main/vite.config.ts",
     "electron:build:preload": "vite build --config ./electron/preload/vite.config.ts",