fix: fresh DATA_DIR=/data/v2 (DB corrupted from path switches)

fix: run app as root (no su-exec), drop chown on /data bucket

fix: DATA_DIR=/data/9router-data (subdir in HF bucket to avoid mount readonly issue)

fix: store persistent data on HF bucket at /data (DATA_DIR=/data)

fix: use port 7860 for HF Space

feat: configurable stream stall timeout + per-provider UI