feat(sms): add selectable provider strategy

README.md

@@ -1,11 +1,11 @@
 # Gapido Backend Code Challenge
 
-Python gRPC OTP authentication service with MongoDB, Redis, RabbitMQ, and a Kavenegar SMS adapter.
+Python gRPC OTP authentication service with MongoDB, Redis, RabbitMQ, and selectable SMS providers.
 
 ## Architecture
 
 - `auth-service`: async `grpc.aio` API for OTP login, token refresh, token revocation, and RBAC demo methods.
-- `sms-worker`: RabbitMQ consumer that sends OTP messages through Kavenegar.
+- `sms-worker`: RabbitMQ consumer that sends OTP messages through the configured SMS provider.
 - MongoDB stores users and refresh-token sessions.
 - Redis stores OTP hashes, TTL, verification attempts, and OTP request rate limits.
 - RabbitMQ decouples authentication from SMS delivery.
@@ -19,6 +19,19 @@ docker compose up --build
 
 The gRPC service listens on `localhost:50051`. RabbitMQ management is available at `http://localhost:15672` with `guest` / `guest`.
 
+## SMS Provider
+
+The SMS integration uses the Strategy pattern behind the `SmsClient` port. Select the provider with:
+
+```env
+SMS_PROVIDER=kavenegar
+```
+
+Supported values:
+
+- `kavenegar`: uses `KAVENEGAR_API_KEY` and `KAVENEGAR_LOGIN_TEMPLATE`.
+- `sms_ir`: uses `SMS_IR_API_KEY` and `SMS_IR_VERIFY_TEMPLATE_ID`.
+
 ## Local Development
 
 ```bash
@@ -50,5 +63,4 @@ authorization: Bearer <access_token>
 - OTP requests are rate-limited per mobile number and client identity.
 - Refresh tokens are opaque random values; only SHA-256 hashes are persisted.
 - Refresh tokens rotate on use.
-- Kavenegar is hidden behind an adapter and mocked in tests.
-
+- SMS providers are hidden behind adapters and mocked in tests.