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/controller/functions/toast.dart

@@ -0,0 +1,35 @@
+import 'package:flutter/material.dart';
+import 'package:get/get.dart';
+import 'package:sefer_driver/constant/colors.dart';
+import 'package:sefer_driver/constant/style.dart';
+
+class Toast {
+  static void show(BuildContext context, String message, Color color) {
+    final snackBar = SnackBar(
+      clipBehavior: Clip.antiAliasWithSaveLayer,
+      backgroundColor: color,
+      elevation: 3,
+      content: Text(
+        message,
+        style: AppStyle.title.copyWith(color: AppColor.secondaryColor),
+      ),
+      behavior: SnackBarBehavior.floating,
+      animation: const AlwaysStoppedAnimation(1.0),
+      shape: RoundedRectangleBorder(
+        borderRadius: BorderRadius.circular(10.0), // Custom border radius
+      ),
+      width: Get.width * .8,
+      // shape: const StadiumBorder(
+      //     side: BorderSide(
+      //   color: AppColor.secondaryColor,
+      //   width: 1.0,
+      //   style: BorderStyle.solid,
+      // )),
+      duration: const Duration(seconds: 2),
+    );
+
+    ScaffoldMessenger.of(context).showSnackBar(
+      snackBar,
+    );
+  }
+}