style: sort Python imports with isort

Add isort configuration (profile=black, line_length=100) to pyproject.toml,
add isort pre-commit hook, and auto-sort imports across all Python source files.

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

python/parsers/kicad_mod_parser.py

@@ -15,8 +15,8 @@ KiCad S-expression file format reference:
   https://dev-docs.kicad.org/en/file-formats/sexpr-intro/index.html#_footprint
 """
 
-import re
 import logging
+import re
 from pathlib import Path
 from typing import Any, Dict, List, Optional, Tuple