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

Closes #7

create_pr.py

@@ -11,17 +11,18 @@ Auth is pulled from the macOS keychain via `git credential fill` for the
 chosen host -- no tokens on the command line.
 
 Examples:
-    create_pr.py --remote dadeschools \\
-        --title "Open generated PDF after creation (#7)" \\
-        --head feat/7-open-pdf-2234ddf5 --base feat/4-5-24-validations \\
+    create_pr.py --remote dadeschools \
+        --title "Open generated PDF after creation (#7)" \
+        --head feat/7-open-pdf-2234ddf5 --base feat/4-5-24-validations \
         --body "Closes #7"
 
     create_pr.py --remote prgs --title "Fix X" --head fix/x --body-file body.md
 
     # override any field of a known remote, or point at an arbitrary repo:
-    create_pr.py --host gitea.example.com --org Foo --repo Bar \\
+    create_pr.py --host gitea.example.com --org Foo --repo Bar \
         --title "..." --head topic
 """
+import os
 import sys
 import json
 import base64
@@ -29,6 +30,12 @@ import argparse
 import urllib.request
 import urllib.error
 
+# 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_credentials, resolve_remote, add_remote_args