feat: 新增 MQTT 配置支持

- 新增 MQTTConfig 配置类
- 支持 broker_host/port/client_id 等配置
- 支持环境变量覆盖配置

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

app/config.py

@@ -1,3 +1,6 @@
+"""
+配置管理
+"""
 import os
 from pathlib import Path
 from typing import Optional
@@ -7,11 +10,13 @@ from pydantic import BaseModel
 
 @dataclass
 class DatabaseConfig:
+    """数据库配置"""
     url: str = "sqlite:///./data/alert_platform.db"
 
 
 @dataclass
 class OSSConfig:
+    """OSS 存储配置"""
     access_key_id: str = ""
     access_key_secret: str = ""
     endpoint: str = "oss-cn-hangzhou.aliyuncs.com"
@@ -21,6 +26,7 @@ class OSSConfig:
 
 @dataclass
 class AppConfig:
+    """应用配置"""
     host: str = "0.0.0.0"
     port: int = 8000
     debug: bool = True
@@ -28,18 +34,36 @@ class AppConfig:
 
 @dataclass
 class AIModelConfig:
+    """AI 模型配置"""
     endpoint: str = ""
     api_key: str = ""
 
 
+@dataclass
+class MQTTConfig:
+    """MQTT 配置"""
+    broker_host: str = "localhost"
+    broker_port: int = 1883
+    client_id: str = "alert_platform"
+    username: str = ""
+    password: str = ""
+    alert_topic: str = "edge/alert/#"
+    heartbeat_topic: str = "edge/alert/heartbeat/#"
+    qos: int = 1
+    enabled: bool = True
+
+
 class Settings(BaseModel):
+    """全局配置"""
     database: DatabaseConfig = DatabaseConfig()
     oss: OSSConfig = OSSConfig()
     app: AppConfig = AppConfig()
     ai_model: AIModelConfig = AIModelConfig()
+    mqtt: MQTTConfig = MQTTConfig()
 
 
 def load_settings() -> Settings:
+    """从环境变量加载配置"""
     from dotenv import load_dotenv
     load_dotenv()
 
@@ -63,6 +87,17 @@ def load_settings() -> Settings:
             endpoint=os.getenv("AI_MODEL_ENDPOINT", ""),
             api_key=os.getenv("AI_MODEL_API_KEY", ""),
         ),
+        mqtt=MQTTConfig(
+            broker_host=os.getenv("MQTT_BROKER_HOST", "localhost"),
+            broker_port=int(os.getenv("MQTT_BROKER_PORT", "1883")),
+            client_id=os.getenv("MQTT_CLIENT_ID", "alert_platform"),
+            username=os.getenv("MQTT_USERNAME", ""),
+            password=os.getenv("MQTT_PASSWORD", ""),
+            alert_topic=os.getenv("MQTT_ALERT_TOPIC", "edge/alert/#"),
+            heartbeat_topic=os.getenv("MQTT_HEARTBEAT_TOPIC", "edge/alert/heartbeat/#"),
+            qos=int(os.getenv("MQTT_QOS", "1")),
+            enabled=os.getenv("MQTT_ENABLED", "true").lower() == "true",
+        ),
     )