feat: Pydantic schemas and EMQX REST API client

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

tests/test_emqx_api.py

@@ -0,0 +1,55 @@
+import pytest
+import httpx
+from unittest.mock import AsyncMock, patch
+
+from mqtt_home.emqx_api import EmqxApiClient
+from mqtt_home.config import Settings
+
+
+@pytest.fixture
+def settings():
+    return Settings(
+        mqtt_host="localhost",
+        emqx_api_url="http://localhost:18083/api/v5",
+        emqx_api_key="test-key",
+        emqx_api_secret="test-secret",
+        database_url="sqlite+aiosqlite:///:memory:",
+    )
+
+
+@pytest.fixture
+def emqx_client(settings):
+    return EmqxApiClient(settings)
+
+
+def _make_response(status_code: int, json_data: dict) -> httpx.Response:
+    request = httpx.Request("GET", "http://localhost:18083/api/v5/test")
+    return httpx.Response(status_code, json=json_data, request=request)
+
+
+async def test_get_broker_status(emqx_client):
+    with patch.object(emqx_client._client, "get", new_callable=AsyncMock) as mock_get:
+        mock_get.return_value = _make_response(
+            200, {"data": {"uptime": 12345, "version": "5.0.0"}}
+        )
+        result = await emqx_client.get_broker_status()
+        assert result["uptime"] == 12345
+
+
+async def test_get_clients(emqx_client):
+    with patch.object(emqx_client._client, "get", new_callable=AsyncMock) as mock_get:
+        mock_get.return_value = _make_response(
+            200, {"data": [{"clientid": "dev1", "connected": True}]}
+        )
+        result = await emqx_client.get_clients()
+        assert len(result) == 1
+        assert result[0]["clientid"] == "dev1"
+
+
+async def test_get_topics(emqx_client):
+    with patch.object(emqx_client._client, "get", new_callable=AsyncMock) as mock_get:
+        mock_get.return_value = _make_response(
+            200, {"data": [{"topic": "home/light"}]}
+        )
+        result = await emqx_client.get_topics()
+        assert len(result) == 1