fix: isolate immutable session context tests (#714)

tests/test_commit_payloads.py

@@ -227,6 +227,7 @@ class TestCommitPayloads(unittest.TestCase):
     @patch("mcp_server.api_request")
     @patch("mcp_server.get_auth_header", return_value="token author-pass")
     def test_commit_files_traversal_blocked(self, _auth, mock_api):
+        mock_api.return_value = {"login": "author-user"}
         # Remove active lock file to ensure it fails on traversal/invalid locks
         os.remove(self.lock_file_path)
 
@@ -248,6 +249,7 @@ class TestCommitPayloads(unittest.TestCase):
     @patch("mcp_server.api_request")
     @patch("mcp_server.get_auth_header", return_value="token author-pass")
     def test_commit_files_outside_scope_blocked(self, _auth, mock_api):
+        mock_api.return_value = {"login": "author-user"}
         with patch.dict(os.environ, self._env("full-author"), clear=True):
             with self.assertRaises(ValueError) as ctx:
                 mcp_server.gitea_commit_files(
@@ -266,6 +268,7 @@ class TestCommitPayloads(unittest.TestCase):
     @patch("mcp_server.api_request")
     @patch("mcp_server.get_auth_header", return_value="token author-pass")
     def test_commit_files_multiple_sources_blocked(self, _auth, mock_api):
+        mock_api.return_value = {"login": "author-user"}
         with patch.dict(os.environ, self._env("full-author"), clear=True):
             with self.assertRaises(ValueError) as ctx:
                 mcp_server.gitea_commit_files(