fix: address post-audit review findings across docs and source

ci(hooks): add pre-commit config with ruff and mypy hooks

style(state): remove unused pytest import from test_state

test(ml): add integration test with real model file

test(utils): add tests for HTML escaping utilities

test(state): add tests for session state management functions

test(database): add integration test for CSV column validation

fix(ml): add input shape validation before model prediction

refactor(ml): decouple Streamlit caching from model module

refactor(database): decouple Streamlit caching from connection module

refactor(validation): remove SQL injection guards (no SQL database exists)

refactor(dead-code): remove unused PlayerStats Pydantic model

fix: restore player search functionality and add HF frontmatter

Fix import sorting in tests/conftest.py to satisfy CI

Address reviewer feedback: fix grammar, path resolution, and sampling logic

Transition data layer to local CSV using pandas

Fix CI failures: type annotations, linting, and coverage threshold

Refactor app with security fixes, error handling, and type safety