feat: Implement hardware, pose, and stream services for WiFi-DensePose API

- Added HardwareService for managing router interfaces, data collection, and monitoring.
- Introduced PoseService for processing CSI data and estimating poses using neural networks.
- Created StreamService for real-time data streaming via WebSocket connections.
- Implemented initialization, start, stop, and status retrieval methods for each service.
- Added data processing, error handling, and statistics tracking across services.
- Integrated mock data generation for development and testing purposes.

src/api/__init__.py

@@ -2,6 +2,6 @@
 WiFi-DensePose FastAPI application package
 """
 
-from .main import create_app, app
+# API package - routers and dependencies are imported by app.py
 
-__all__ = ["create_app", "app"]
+__all__ = []