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/package.json

@@ -0,0 +1,18 @@
+{
+  "name": "faceai",
+  "private": true,
+  "workspaces": [
+    "apps/frontend",
+    "apps/backend"
+  ],
+  "scripts": {
+    "dev": "concurrently \"npm:dev:backend\" \"npm:dev:frontend\"",
+    "dev:backend": "npm run dev --workspace @regalami/faceai-backend",
+    "dev:frontend": "npm run dev --workspace @regalami/faceai-frontend",
+    "build": "npm run build --workspace @regalami/faceai-frontend && npm run build --workspace @regalami/faceai-backend",
+    "start": "npm run start --workspace @regalami/faceai-backend"
+  },
+  "devDependencies": {
+    "concurrently": "^9.1.2"
+  }
+}