feat: optimize for HF Spaces deployment

fix: resolve ModuleNotFoundError and simplify CI/CD

fix(docker): install torchvision from CPU index to resolve torchvision::nms operator error

fix(deploy): upgrade Python to 3.11 and PyTorch to >=2.6.0 to address CVE-2025-32434 security load restriction

fix(deploy): upgrade frontend builder Node version to 20-alpine to support Vite build requirements

fix(deploy): update base python image to slim-bookworm to fix EOL buster apt-get 404 error

deploy: update Dockerfile for Hugging Face non-root user permissions and port 7860

Initial commit: BAIF Offline Translation Portal with production Dockerfile and recent optimizations