feat: Add FaceAI integration with handoff and return functionality

- Introduced a new workspace for FaceAI in package.json.
- Implemented FaceAI handoff logic in faceai_handoff.php, including identity verification and token signing.
- Created faceai_return.php to handle return requests from FaceAI, validating tokens and forwarding results.
- Developed faceai_simulator.php and faceai_simulator_view.php for simulating the FaceAI interface with demo photos.
- Enhanced rus-ecom-240621.js to support new FaceAI features, including dynamic URL building and button integration.
- Added faceai_config.php for configuration management, including environment variable handling and utility functions.
- Updated HTML structure and styles in simulator view for better user experience.

faceai/apps/backend/package.json

@@ -0,0 +1,15 @@
+{
+  "name": "@regalami/faceai-backend",
+  "private": true,
+  "type": "module",
+  "scripts": {
+    "dev": "node --watch src/server.js",
+    "build": "node -e \"console.log('backend build not required')\"",
+    "start": "node src/server.js"
+  },
+  "dependencies": {
+    "cookie-parser": "^1.4.7",
+    "cors": "^2.8.5",
+    "express": "^4.21.2"
+  }
+}