refactor: reorganize Vite config into modular files

Split monolithic vite.config.mjs into separate config files:
- vite.config.web.mts
- vite.config.electron.mts
- vite.config.capacitor.mts
- vite.config.pywebview.mts
- vite.config.common.mts
- vite.config.utils.mts

Updates:
- Modify package.json scripts to use specific config files
- Add electron-builder as dev dependency
- Update electron build configuration
- Fix electron resource paths
- Remove old vite.config.mjs and utils.js

This change improves maintainability by:
- Separating concerns for different build targets
- Making build configurations more explicit
- Reducing complexity in individual config files

main.js

@@ -0,0 +1,29 @@
+const { app, BrowserWindow } = require('electron');
+const path = require('path');
+
+function createWindow() {
+  const win = new BrowserWindow({
+    width: 1200,
+    height: 800,
+    webPreferences: {
+      nodeIntegration: true,
+      contextIsolation: false
+    }
+  });
+
+  win.loadFile(path.join(__dirname, 'dist-electron/www/index.html'));
+}
+
+app.whenReady().then(createWindow);
+
+app.on('window-all-closed', () => {
+  if (process.platform !== 'darwin') {
+    app.quit();
+  }
+});
+
+app.on('activate', () => {
+  if (BrowserWindow.getAllWindows().length === 0) {
+    createWindow();
+  }
+});