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/commands/symbol_creator.py

@@ -12,9 +12,9 @@ KiCAD 9 .kicad_sym format:
   - All coordinates in mm, 2.54mm grid typical for schematic symbols
 """
 
+import logging
 import os
 import re
-import logging
 from pathlib import Path
 from typing import Any, Dict, List, Optional