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

src/main.web.ts

@@ -0,0 +1,5 @@
+import { initializeApp } from "./main.common";
+import "./registerServiceWorker"; // Web PWA support
+
+const app = initializeApp();
+app.mount("#app");