feat: Gemini AI (doc OCR + face match) + role-assignment endpoints

- GeminiService (integrations/gemini, @Global): extractDocument (OCR fields) + faceMatch; graceful if no GEMINI_API_KEY
- documents: face-match now real via Gemini; POST /admin/documents/:id/ocr extracts fields for CS auto-fill
- roles: PATCH /admin/users/:id/role (admin) + POST /platform/users/role (bootstrap via x-platform-secret)
- config: gemini + platform.secret; .env.example entries

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

apps/driver/lib/models/model/locations.dart

@@ -0,0 +1,34 @@
+class CarLocationModel {
+  String id;
+  String driverId;
+  double latitude;
+  double heading;
+  double speed;
+  double longitude;
+  DateTime createdAt;
+  DateTime updatedAt;
+
+  CarLocationModel({
+    required this.id,
+    required this.driverId,
+    required this.latitude,
+    required this.longitude,
+    required this.heading,
+    required this.speed,
+    required this.createdAt,
+    required this.updatedAt,
+  });
+
+  factory CarLocationModel.fromJson(Map<String, dynamic> json) {
+    return CarLocationModel(
+      id: json['id'],
+      driverId: json['driver_id'],
+      latitude: double.parse(json['latitude'].toString()),
+      longitude: double.parse(json['longitude'].toString()),
+      heading: double.parse(json['heading'].toString()),
+      speed: double.parse(json['speed'].toString()),
+      createdAt: DateTime.parse(json['created_at']),
+      updatedAt: DateTime.parse(json['updated_at']),
+    );
+  }
+}