feat(lint): Add automatic detection for function-level imports

Add ruff PLC (pylint conventions) rule to automatically detect
function-level imports, which violates PEP 8 guidelines.

Changes:
- Add PLC rule group to ruff select (includes PLC0415: import-outside-toplevel)
- Move urllib.parse import to top-level in src/sharepoint_auth.py
- Exclude PLC0415 from tests/** for legitimate test isolation needs
  (e.g., config reload, mock ordering)

This prevents future violations like the one caught by Gemini Code Assist.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Author: k-ibaraki

pyproject.toml

@@ -72,13 +72,14 @@ target-version = "py312"
 
 [tool.ruff.lint]
 select = [
-    "E",  # pycodestyle errors
-    "W",  # pycodestyle warnings
-    "F",  # pyflakes
-    "I",  # isort
-    "B",  # flake8-bugbear
-    "C4", # flake8-comprehensions
-    "UP", # pyupgrade
+    "E",   # pycodestyle errors
+    "W",   # pycodestyle warnings
+    "F",   # pyflakes
+    "I",   # isort
+    "B",   # flake8-bugbear
+    "C4",  # flake8-comprehensions
+    "UP",  # pyupgrade
+    "PLC", # pylint conventions (includes PLC0415: import-outside-toplevel)
 ]
 ignore = [
     "E501",  # line too long, handled by black
@@ -89,6 +90,7 @@ ignore = [
 
 [tool.ruff.lint.per-file-ignores]
 "__init__.py" = ["F401"]
+"tests/**/*.py" = ["PLC0415"]  # Allow function-level imports in tests for mocking/isolation
 
 [tool.ruff.format]
 quote-style = "double"

src/sharepoint_auth.py

@@ -7,6 +7,7 @@
 import time
 import uuid
 from pathlib import Path
+from urllib.parse import urlparse
 
 import jwt
 import requests
@@ -132,8 +133,6 @@ def _request_access_token(self) -> dict[str, str]:
             )
 
             # SharePointサイトのテナント名を取得
-            from urllib.parse import urlparse
-
             parsed_url = urlparse(self.site_url)
             tenant_name = parsed_url.netloc.split(".sharepoint.com")[0]
             scope = f"https://{tenant_name}.sharepoint.com/.default"