feat: Add camera device support with HLS streaming integration

[Tobiwan91]

Implements camera device integration for grow room monitoring,
enabling real-time video streaming and still image capture functionality.

Backend Changes:

• New OGBCamera device class with HLS stream URL retrieval
• Camera entity binding and lifecycle management
• Event emission on camera detection (camera_detected event)
• Still image URL fallback for camera preview
• Device base class extended with camera entity category support
• OGBParams updated to detect camera entities (camera., webcam, cam, view, monitor)
• OGBDeviceManager device registry updated to register Camera devices

Frontend Changes:

• Camera card component for live stream display
• HLS video player integration with fallback to still images
• Camera state management through React context
• Real-time camera status updates via WebSocket events
• Responsive camera UI for dashboard integration

Technical Details:

• Cameras are detected by area assignment in Home Assistant
• Supports HLS streaming via /api/camera_proxy_stream endpoint
• Provides still image access via /api/camera_proxy endpoint
• Emits camera_detected event with entity_id, device_name, room, and friendly_name
• Camera entities identified by "camera." prefix and device label keywords

This enables users to monitor their grow rooms in real-time through the
OpenGrowBox dashboard, enhancing visibility and control over grow operations.