feat: Pydantic schemas and EMQX REST API client

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

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

src/mqtt_home/schemas.py

@@ -0,0 +1,70 @@
+from datetime import datetime
+from typing import Optional
+from pydantic import BaseModel, Field
+
+
+class DeviceCreate(BaseModel):
+    name: str
+    type: str = "switch"
+    protocol: str = "custom"
+    mqtt_topic: str
+    command_topic: Optional[str] = None
+
+
+class DeviceUpdate(BaseModel):
+    name: Optional[str] = None
+    type: Optional[str] = None
+    command_topic: Optional[str] = None
+
+
+class DeviceCommand(BaseModel):
+    payload: str
+
+
+class DeviceResponse(BaseModel):
+    id: str
+    name: str
+    type: str
+    protocol: str
+    mqtt_topic: str
+    command_topic: Optional[str] = None
+    state: Optional[str] = None
+    is_online: bool
+    last_seen: Optional[datetime] = None
+    created_at: datetime
+    updated_at: datetime
+
+    model_config = {"from_attributes": True}
+
+
+class DeviceLogResponse(BaseModel):
+    id: int
+    device_id: str
+    direction: str
+    topic: str
+    payload: str
+    timestamp: datetime
+
+    model_config = {"from_attributes": True}
+
+
+class BrokerClient(BaseModel):
+    clientid: str
+    username: Optional[str] = None
+    ip_address: Optional[str] = None
+    connected: bool
+    keepalive: int
+    proto_ver: Optional[int] = None
+    clean_start: Optional[bool] = None
+
+
+class BrokerTopic(BaseModel):
+    topic: str
+    node: Optional[str] = None
+
+
+class DashboardStats(BaseModel):
+    total_devices: int
+    online_devices: int
+    offline_devices: int
+    recent_logs: list[DeviceLogResponse]