feat: initialize frontend with Vite and PWA support

- Add index.html as the main entry point for the application.
- Create package.json to manage dependencies and scripts for development.
- Include favicon.svg for the application icon.
- Configure PWA assets generation with pwa-assets.config.js.
- Implement counter functionality in counter.js with notification on reaching 5.
- Add JavaScript logo SVG for branding.
- Set up main.js to render the application and handle user interactions.
- Create notification.js to manage browser notifications.
- Implement PWA registration and update handling in pwa.js.
- Style the application with a new style.css file.
- Configure Vite with PWA plugin in vite.config.js for service worker and manifest settings.

backend/.gitignore

@@ -0,0 +1,34 @@
+# dependencies (bun install)
+node_modules
+
+# output
+out
+dist
+*.tgz
+
+# code coverage
+coverage
+*.lcov
+
+# logs
+logs
+_.log
+report.[0-9]_.[0-9]_.[0-9]_.[0-9]_.json
+
+# dotenv environment variable files
+.env
+.env.development.local
+.env.test.local
+.env.production.local
+.env.local
+
+# caches
+.eslintcache
+.cache
+*.tsbuildinfo
+
+# IntelliJ based IDEs
+.idea
+
+# Finder (MacOS) folder config
+.DS_Store