Add depth-based wall/door detection

Add more indoor obstacles, lower detection threshold to 0.25

Switch to gradio 5.x - fixes localhost check and gradio_client bugs

Fix: add share=False, pin gradio_client, set GRADIO_SERVER_NAME

Fix: add libgles2 libegl1 for mediapipe

Fix: pin gradio==4.44.0 and huggingface_hub==0.25.0

Fix: replace libgl1-mesa-glx with libgl1

Fix: use Docker with Python 3.11 to avoid audioop error

Clean up: remove tar.gz, fix gitignore

Configure for Hugging Face Spaces deployment

Blind navigation MVP