fix(providers): implement thread-safe obstacle data access in D435Provider

[xieNniu]

Added thread-safe protection for obstacle point cloud data in D435Provider to prevent race conditions when accessing shared state from multiple threads.

Changes:

• Introduced threading.Lock to protect read/write operations on the obstacle data structure
• Converted obstacle to private attribute _obstacle with a thread-safe @property getter method
• Enhanced error logging in obstacle_callback with exc_info=True for better debugging context
• Added comprehensive NumPy-style docstring to __init__ method documenting initialization flow and thread safety mechanisms
• Updated class-level docstring to describe thread-safe characteristics and asynchronous callback behavior

Technical Details:

• The obstacle_callback method runs asynchronously in a separate thread when Zenoh receives point cloud data from the camera/realsense2_camera_node/depth/obstacle_point topic
• Without thread synchronization, concurrent access to self.obstacle from the callback thread and main thread could lead to race conditions
• The lock ensures atomic updates when processing point cloud data and calculating obstacle coordinates (x, y, z, angle, distance)

Files Modified:

• src/providers/d435_provider.py

[Wanbogang]

Can you please resolve the conflicts?

[Wanbogang]

@xieNniu
Thread locking is technically correct, but for this use case it adds complexity without significant benefit. Consider simplifying it.

[codecov]

Codecov Report

❌ Patch coverage is 27.27273% with 8 lines in your changes missing coverage. Please review.
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
src/providers/d435_provider.py	27.27%	8 Missing ⚠️

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