feat(demo): add auth flow UI service

README.md

@@ -17,7 +17,7 @@ cp .env.example .env
 docker compose up --build
 ```
 
-The gRPC service listens on `localhost:50051`. RabbitMQ management is available at `http://localhost:15672` with `guest` / `guest`.
+The gRPC service listens on `localhost:50051`. The demo UI is available at `http://localhost:8080`. RabbitMQ management is available at `http://localhost:15672` with `guest` / `guest`.
 
 ## SMS Provider
 
@@ -31,6 +31,18 @@ Supported values:
 
 - `kavenegar`: uses `KAVENEGAR_API_KEY` and `KAVENEGAR_LOGIN_TEMPLATE`.
 - `sms_ir`: uses `SMS_IR_API_KEY` and `SMS_IR_VERIFY_TEMPLATE_ID`.
+- `debug`: local-only provider that stores the latest OTP in Redis for the demo UI.
+
+## Demo UI
+
+`demo-app` is a small FastAPI backend-for-frontend that calls `auth-service` over gRPC. It demonstrates how another microservice consumes the auth service.
+
+Available browser actions:
+
+- Request and verify OTP.
+- Fetch the local debug OTP when `DEMO_ENABLE_DEBUG_OTP=true`.
+- Call public, authenticated-user, and admin-only gRPC methods.
+- Refresh and revoke tokens.
 
 ## Local Development