align app.py with original run.py: BGR->RGB fix, lower wall threshold

replace gradio with fastapi+html, clean Dockerfile

fix: upgrade to gradio 4.44.1, remove broken theme

fix: bind Gradio to 0.0.0.0:7860 for Docker

fix: correct weights filename to faster_rcnn_latest.pth

fix: mmdet 3.x stack + DetDataSample API in app.py

add model, config, submodule and Space files