chore: consolidate to single ruff config in root pyproject.toml

- Merge web ruff settings (select E/F/I/UP, line-length 100) into root config
- Remove [tool.ruff] section from web/pyproject.toml
- Remove "web" from root ruff exclude list
- Simplify pre-commit hook to one command: ruff check .
- Update CI to use: uv run ruff check . (from repo root)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

tests/test_cot_extraction.py

@@ -7,7 +7,6 @@ from unittest.mock import MagicMock
 
 from cftc_cot.normalize import find_csv_inner_filename, normalize_zipped_csv
 
-
 # =============================================================================
 # normalize.py
 # =============================================================================