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/ios/Runner/Constants.swift

@@ -0,0 +1,12 @@
+//
+//  Constants.swift
+//  Runner
+//
+//  Created by Hamza Aleghwairyeen on 24/02/2025.
+//
+
+import Foundation
+
+struct Constants {
+    static let googleMapsAPIKey = "AIzaSyCyfwRXTwSTLOFQSQgN5p7QZgGJVZnEKq0"
+}