feat: Implement backend API and basic frontend structure

Adds initial backend API endpoints for fetching users and attendances, including basic filtering. Sets up the frontend routing with a layout component and includes placeholder pages for dashboard, users, and login. Refactors the README for local development setup.

vite.config.ts

@@ -0,0 +1,23 @@
+import path from 'path';
+import { defineConfig, loadEnv } from 'vite';
+import react from '@vitejs/plugin-react';
+
+export default defineConfig(({ mode }) => {
+    const env = loadEnv(mode, '.', '');
+    return {
+      server: {
+        port: 3000,
+        host: '0.0.0.0',
+      },
+      plugins: [react()],
+      define: {
+        'process.env.API_KEY': JSON.stringify(env.GEMINI_API_KEY),
+        'process.env.GEMINI_API_KEY': JSON.stringify(env.GEMINI_API_KEY)
+      },
+      resolve: {
+        alias: {
+          '@': path.resolve(__dirname, '.'),
+        }
+      }
+    };
+});