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/n8n/handlers/variables.py

@@ -5,6 +5,7 @@ from typing import Any
 
 from plugins.n8n.client import N8nClient
 
+
 def get_tool_specifications() -> list[dict[str, Any]]:
     """Return tool specifications for ToolGenerator"""
     return [
@@ -92,6 +93,7 @@ def get_tool_specifications() -> list[dict[str, Any]]:
         },
     ]
 
+
 async def list_variables(client: N8nClient, limit: int = 100, cursor: str | None = None) -> str:
     try:
         response = await client.list_variables(limit=limit, cursor=cursor)
@@ -106,6 +108,7 @@ async def list_variables(client: N8nClient, limit: int = 100, cursor: str | None
     except Exception as e:
         return json.dumps({"success": False, "error": str(e)}, indent=2)
 
+
 async def get_variable(client: N8nClient, key: str) -> str:
     try:
         variable = await client.get_variable(key)
@@ -119,6 +122,7 @@ async def get_variable(client: N8nClient, key: str) -> str:
     except Exception as e:
         return json.dumps({"success": False, "error": str(e)}, indent=2)
 
+
 async def create_variable(client: N8nClient, key: str, value: str) -> str:
     try:
         await client.create_variable(key, value)
@@ -133,6 +137,7 @@ async def create_variable(client: N8nClient, key: str, value: str) -> str:
     except Exception as e:
         return json.dumps({"success": False, "error": str(e)}, indent=2)
 
+
 async def update_variable(client: N8nClient, key: str, value: str) -> str:
     try:
         await client.update_variable(key, value)
@@ -147,6 +152,7 @@ async def update_variable(client: N8nClient, key: str, value: str) -> str:
     except Exception as e:
         return json.dumps({"success": False, "error": str(e)}, indent=2)
 
+
 async def delete_variable(client: N8nClient, key: str) -> str:
     try:
         await client.delete_variable(key)
@@ -154,6 +160,7 @@ async def delete_variable(client: N8nClient, key: str) -> str:
     except Exception as e:
         return json.dumps({"success": False, "error": str(e)}, indent=2)
 
+
 async def set_variables(client: N8nClient, variables: dict[str, str]) -> str:
     try:
         created, updated, failed = [], [], []