fix(ci): fix black/ruff failures, add CoC and PR template

- Fix Python formatting (sync no longer strips blank lines from .py files)
- Remove test_community_build.py (tests private sync module)
- Fix ruff warnings in test files
- Add CODE_OF_CONDUCT.md
- Add .github/PULL_REQUEST_TEMPLATE.md

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

plugins/directus/client.py

@@ -40,6 +40,7 @@ from typing import Any
 
 import aiohttp
 
+
 def _ensure_list(value: Any) -> list[str]:
     """Ensure value is a list. If string, wrap in list."""
     if value is None:
@@ -50,6 +51,7 @@ def _ensure_list(value: Any) -> list[str]:
         return [value]
     return [str(value)]
 
+
 class DirectusClient:
     """
     Directus Self-Hosted API client.