feat(demo): add auth flow UI service

tests/test_debug_sms_client.py

@@ -0,0 +1,20 @@
+from gapido_auth.infrastructure.debug_sms_client import DebugSmsClient, debug_sms_key
+
+
+class FakeDebugStore:
+    def __init__(self) -> None:
+        self.values: dict[str, tuple[int, str]] = {}
+
+    async def setex(self, name: str, time: int, value: str) -> object:
+        self.values[name] = (time, value)
+        return True
+
+
+async def test_debug_sms_client_stores_latest_otp() -> None:
+    store = FakeDebugStore()
+    client = DebugSmsClient(store, ttl_seconds=300)
+
+    await client.send_otp("989120000000", "123456", "debug-otp")
+
+    assert store.values[debug_sms_key("989120000000")] == (300, "123456")
+