fix: resolve pre-commit hook issues for mypy and root-level files

- Fix mypy duplicate module conflict by excluding python/commands/board.py
- Add import-untyped to mypy disabled error codes
- Use explicit_package_bases for proper module resolution
- Auto-format root-level download_jlcpcb.py and test-router.js

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

pyproject.toml

@@ -18,7 +18,10 @@ warn_unused_configs = true
 ignore_missing_imports = true
 check_untyped_defs = false
 disallow_untyped_defs = false
+explicit_package_bases = true
+mypy_path = "."
 disable_error_code = [
+    "import-untyped",
     "arg-type",
     "attr-defined",
     "union-attr",