Fix requirements.txt encoding and add cachetools dependency

Optimize app for 500+ users: Add multithreaded CSV uploads and LRU/TTL caching for Dashboards and NLP engine

Fix login loop for HF Spaces iframe using SameSite=None

Fix Gunicorn startup command to use app factory

Completely rewrite requirements.txt using write_to_file to guarantee clean UTF-8

Add missing scikit-learn dependency

Completely rewrite requirements.txt to fix Windows encoding null bytes

Fix encoding of requirements.txt

Add missing Flask-Mail dependency

Remove redundant create_admin.py from Dockerfile

Fix database connection to use SQLite on Hugging Face Spaces

Add Hugging Face configuration to README

Add Dockerfile for Hugging Face deployment

Initial commit