style: apply pre-commit autofixes (EOF, ruff-format)

fix(typing): split adapter vars in /readyz to satisfy mypy

fix(api): make adapter non-optional within branch and annotate pipeline for mypy

fix(pipeline): align backend-frontend schema and stabilize SQL flow

style: format code with ruff

fix(main): load .env before FastAPI imports (noqa E402)

feat(demo): add initial Gradio UI with optional SQLite upload

Fix some typo

style: format code with ruff

init: NL2SQL Copilot base with API and Dockerfile