FINAL FIX: Enable Face Verification weights and fix 0-byte image serving

Fix permission error: switch from /app to /home/user in build script

fix: pin tensorflow-cpu==2.15.1, add 5min download timeout to prevent build hang

feat: enable retinaface detector, download retinaface.h5 from HF Hub during build

fix: stop 500 crash + reliable model download from HF Hub

fix: OOM fix - models baked into Docker image, mobile responsive, 1 worker