Fix #23: JWT storage consistency across all Flutter apps

- siro_admin: added FlutterSecureStorage write alongside GetStorage
- siro_service: added FlutterSecureStorage write in login + guest JWT flows
- siro_rider: added FlutterSecureStorage write in guest + token-refresh flows
  (full-credential login already wrote to both)
- siro_driver: already wrote to both (no change needed)
- All apps now write JWT to both GetStorage and FlutterSecureStorage

siro_rider/lib/controller/auth/login_controller.dart

@@ -126,13 +126,13 @@ class LoginController extends GetxController {
           if (jwt != null) {
             // نشفر الـ JWT بالتشفير الثلاثي قبل التخزين في GetStorage
             box.write(BoxName.jwt, c(jwt));
+            storage.write(key: BoxName.jwt, value: c(jwt));
           }
 
           await EncryptionHelper.initialize();
         }
       } else {
-        // ── مستخدم موجود: تجديد التوكن ────────────────────────
-        await EncryptionHelper.initialize();
+        // ── مستخدم موجود: تجديد التوكن
 
         var payload = {
           'id': box.read(BoxName.passengerID),
@@ -158,6 +158,7 @@ class LoginController extends GetxController {
 
           if (jwt != null) {
             box.write(BoxName.jwt, c(jwt));
+            storage.write(key: BoxName.jwt, value: c(jwt));
           }
         }
       }