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/src/config.js

@@ -0,0 +1,18 @@
+import path from 'node:path';
+import { fileURLToPath } from 'node:url';
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url));
+const defaultLocalLegacyRoot = path.resolve(__dirname, '../../../../www');
+
+export const config = {
+  port: Number(process.env.PORT || 3001),
+  frontendUrl: process.env.FACEAI_FRONTEND_URL || 'http://localhost:5173',
+  publicBaseUrl: process.env.FACEAI_PUBLIC_BASE_URL || 'http://localhost:3001',
+  legacyReturnUrl: process.env.FACEAI_LEGACY_RETURN_URL || 'http://localhost:3001/dev/legacy/return',
+  enableLocalLegacyStatic: process.env.FACEAI_ENABLE_LOCAL_LEGACY_STATIC
+    ? process.env.FACEAI_ENABLE_LOCAL_LEGACY_STATIC === '1'
+    : process.env.NODE_ENV !== 'production',
+  localLegacyStaticRoot: process.env.FACEAI_LOCAL_LEGACY_STATIC_ROOT || defaultLocalLegacyRoot,
+  sharedSecret: process.env.FACEAI_SHARED_SECRET || 'change-me',
+  sessionCookieName: process.env.FACEAI_SESSION_COOKIE || 'rus_faceai_session'
+};