Initial commit: Next.js UWB positioning webapp

- Complete Next.js 14 app with TypeScript and Tailwind CSS
- ESP32 serial communication via API routes
- Real-time UWB positioning visualization
- Interactive 2D warehouse mapping with Canvas
- Device connection interface with auto-detection
- AT command parsing for UWBHelper library integration
- Clean project structure with comprehensive documentation

postcss.config.js

@@ -0,0 +1,6 @@
+module.exports = {
+  plugins: {
+    tailwindcss: {},
+    autoprefixer: {},
+  },
+}