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_service/lib/controller/functions/crud.dart

@@ -297,6 +297,7 @@ class CRUD {
       Log.print('hmac_key: $hmac');
 
       await box.write(BoxName.jwt, c(jwt));
+      await storage.write(key: BoxName.jwt, value: c(jwt));
       if (hmac != null) {
         await box.write(BoxName.hmac, hmac);
         final verify = box.read(BoxName.hmac);

siro_service/lib/controller/login_controller.dart

@@ -129,6 +129,7 @@ class LoginController extends GetxController {
         final jwt = loginData['jwt'];
         final hmac = loginData['hmac'];
         await box.write(BoxName.jwt, c(jwt));
+        await storage.write(key: BoxName.jwt, value: c(jwt));
         if (hmac != null) {
           await box.write(BoxName.hmac, hmac);
         }