feat: Document Analyzer, Persistent AI Memory, Multi-language (EN/HI/MR), Dark/Light Theme

fix: HF startup crash from set -u on unset DATABASE_URL in start.sh

fix: prevent HF 502 by removing sklearn import at startup and hardening DB init

fix: remove %(ENV_...)s from supervisord — inherit env from start.sh instead

fix: export default env vars in start.sh to prevent supervisord parsing error on undefined environment variables

fix: resolve AI assistant page client crash by converting to HTTP streaming fallback, passing env vars to supervisord, and add payments feature

Fix: Remove invalid user=1000 from supervisord.conf — HF user 1000 has no username

Deploy to HF Space