Rebrand to SegVision Engine, remove AI terminology, and fix video download extension headers

fix: resolve 'Failed to fetch' by hardening API URL detection and using same-origin relative paths

fix: unified deployment fix with flat routing, Suspense boundaries, and forced static export

fix: restore full content and wrap in Suspense for static build

fix: split dynamic routes into server+client components for static export

refactor: drop nginx+standalone, use static export served by FastAPI on :7860

fix: ensure public directory is tracked for docker build

fix: resolve build-breaking JSX typos and add build robustness

chore: add HF Spaces Docker deployment

chore: remove pycache, env files and lock files

Initial commit — SegVision Video Segmentation App