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

Closes #7

manage_labels.py

@@ -8,8 +8,15 @@ Usage:
     ./manage_labels.py          # create labels, then apply the mapping below
     ./manage_labels.py --dry    # print actions without writing
 """
+import os
 import sys
 
+# 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, api_request, repo_api_url
 
 HOST = "gitea.dadeschools.net"