chore: merge master → dev/video-fer (live camera FER mode)

fix: pin onnxruntime==1.24.2 + cache-bust Dockerfile for FER

refactor: restructure repo into api/ proxy/ web/ training/ docs/

fix: RefObject type for React 19 (TS build fix)

feat: add video FER pipeline with full-stack support

feat: switch to external evoxtral Modal API (no local model)

feat: add HuggingFace Spaces Docker deployment