feat: expand MCP server tools for PR and label management, add helper CLI scripts

Closes #7

close_issue.py

@@ -5,9 +5,16 @@ Usage:
     close_issue.py <issue_number>
     close_issue.py --remote prgs 12
 """
+import os
 import sys
 import argparse
 
+# Auto-execute using the project's local virtual environment Python
+PROJECT_ROOT = os.path.dirname(os.path.abspath(__file__))
+venv_python = os.path.join(PROJECT_ROOT, "venv", "bin", "python3")
+if os.path.exists(venv_python) and sys.executable != venv_python:
+    os.execv(venv_python, [venv_python] + sys.argv)
+
 from gitea_auth import (
     get_auth_header, resolve_remote, add_remote_args,
     api_request, repo_api_url,