Import spaces before torch (ZeroGPU init order requirement)

Fix CLIP BPE vocab download: derive path without importing the broken maskclip package

Download CLIP BPE vocab file missing from FeatUp package

Set TORCH_CUDA_ARCH_LIST=7.5;8.0;8.6;8.9;9.0 for FeatUp runtime install (no GPU visible at app startup on ZeroGPU)

Move FeatUp install to runtime (app.py); drop git+ line from requirements.txt

Reorganize: demo lives in demo/ in the GitHub repo; at Space root we keep app.py+demo.py next to mast3r/ and dust3r/

Initial SAB3R demo release