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

Closes #7

tests/test_prs.py

@@ -0,0 +1,68 @@
+"""Tests for list_prs.py, view_pr.py, and delete_branch.py.
+
+Mocks api_request and credentials.
+"""
+import sys
+import unittest
+from unittest.mock import patch
+
+sys.path.insert(0, str(__import__("pathlib").Path(__file__).resolve().parent.parent))
+import list_prs  # noqa: E402
+import view_pr  # noqa: E402
+import delete_branch  # noqa: E402
+
+
+FAKE_CREDS = "Basic dGVzdHVzZXI6dGVzdHBhc3M="
+
+
+class TestListPRs(unittest.TestCase):
+
+    @patch("list_prs.api_request")
+    @patch("list_prs.get_auth_header", return_value=FAKE_CREDS)
+    def test_list_prs_success(self, _auth, mock_api):
+        mock_api.return_value = [
+            {"number": 1, "title": "PR 1", "head": {"ref": "branch1"}, "base": {"ref": "main"}, "html_url": "http://url1", "mergeable": True}
+        ]
+        rc = list_prs.main([])
+        self.assertEqual(rc, 0)
+        mock_api.assert_called_once()
+
+    @patch("list_prs.api_request", return_value=[])
+    @patch("list_prs.get_auth_header", return_value=FAKE_CREDS)
+    def test_list_prs_empty(self, _auth, mock_api):
+        rc = list_prs.main(["--state", "closed"])
+        self.assertEqual(rc, 0)
+        mock_api.assert_called_once()
+
+
+class TestViewPR(unittest.TestCase):
+
+    @patch("view_pr.api_request")
+    @patch("view_pr.get_auth_header", return_value=FAKE_CREDS)
+    def test_view_pr_success(self, _auth, mock_api):
+        mock_api.return_value = {"number": 1, "title": "PR 1", "state": "open", "user": {"login": "user1"}, "head": {"ref": "branch1"}, "base": {"ref": "main"}, "html_url": "http://url1", "mergeable": True, "body": "PR description"}
+        rc = view_pr.main(["1"])
+        self.assertEqual(rc, 0)
+        mock_api.assert_called_once()
+
+    def test_missing_pr_number_exits(self):
+        with self.assertRaises(SystemExit):
+            view_pr.main([])
+
+
+class TestDeleteBranch(unittest.TestCase):
+
+    @patch("delete_branch.api_request")
+    @patch("delete_branch.get_auth_header", return_value=FAKE_CREDS)
+    def test_delete_branch_success(self, _auth, mock_api):
+        rc = delete_branch.main(["feat/my-branch"])
+        self.assertEqual(rc, 0)
+        mock_api.assert_called_once()
+
+    def test_missing_branch_exits(self):
+        with self.assertRaises(SystemExit):
+            delete_branch.main([])
+
+
+if __name__ == "__main__":
+    unittest.main()