feat: add remote app functionality and environment configuration

- Introduced a new HTML file for the light code demo.
- Added TypeScript definitions for environment variables.
- Implemented remote app logic for both browser and node environments.
- Configured Vite to load environment variables and define KEVISUAL_TOKEN.
- Updated README with relevant information about the project structure and usage.

vite.config.ts

@@ -0,0 +1,15 @@
+import { defineConfig, loadEnv } from 'vite';
+import dotenv from 'dotenv';
+
+dotenv.config();
+export default defineConfig(({ mode }) => {
+  // const env = loadEnv(mode, process.cwd());
+  console.log('KEVISUAL_TOKEN:', mode, process.env.KEVISUAL_TOKEN);
+
+  return {
+    base: '/',
+    define: {
+      'KEVISUAL_TOKEN': JSON.stringify(process.env.KEVISUAL_TOKEN || ''),
+    }
+  };
+});