Add MQTT publish request and response models, and implement publish route

- Introduced MQTTPublishRequest and MQTTPublishResponse models for handling MQTT message publishing.
- Implemented a new POST route for publishing MQTT messages, including error handling and logging.
- Enhanced the StandaloneAutoRecorder with improved logging during manual recording start.
- Updated the frontend to include an MQTT Debug Panel for better monitoring and debugging capabilities.

camera-management-api/usda_vision_system/api/models.py

@@ -334,3 +334,21 @@ class SuccessResponse(BaseModel):
     message: str
     data: Optional[Dict[str, Any]] = None
     timestamp: str = Field(default_factory=lambda: datetime.now().isoformat())
+
+
+class MQTTPublishRequest(BaseModel):
+    """MQTT publish request model"""
+
+    topic: str = Field(..., description="MQTT topic to publish to")
+    payload: str = Field(..., description="Message payload")
+    qos: int = Field(default=0, ge=0, le=2, description="Quality of Service level (0-2)")
+    retain: bool = Field(default=False, description="Whether to retain the message")
+
+
+class MQTTPublishResponse(BaseModel):
+    """MQTT publish response model"""
+
+    success: bool
+    message: str
+    topic: str
+    payload: str