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

Closes #7

list_all_remotes_prs.py

@@ -0,0 +1,37 @@
+#!/usr/bin/env python3
+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, REMOTES, repo_api_url
+
+def main():
+    for name, remote in REMOTES.items():
+        host = remote['host']
+        org = remote['org']
+        repo = remote['repo']
+        print(f"Checking remote: {name} ({host}/{org}/{repo})...")
+        try:
+            auth = get_auth_header(host)
+            if not auth:
+                print(f"  No auth header found for {host}")
+                continue
+            url = f"{repo_api_url(host, org, repo)}/pulls?state=open"
+            prs = api_request("GET", url, auth)
+            if not prs:
+                print("  No open pull requests.")
+            for pr in prs:
+                print(f"  PR #{pr['number']}: {pr['title']}")
+                print(f"    Branch: {pr['head']['ref']} -> {pr['base']['ref']}")
+                print(f"    URL: {pr['html_url']}")
+                print(f"    Mergeable: {pr.get('mergeable')}")
+        except Exception as e:
+            print(f"  Error: {e}")
+
+if __name__ == '__main__':
+    main()