fix: use the FastMCP instance and not HatchMCP

For now, to avoid compatibility issues when deploying MCP hosts from Hatch packages, we reference the `mcp_server.py` script and not the `hatch_mcp_server_entry.py`

Author: LittleCoinCoin

hatch/cli_hatch.py

@@ -89,8 +89,8 @@ def get_package_mcp_server_config(env_manager: HatchEnvironmentManager, env_name
         package_service = PackageService(metadata)
 
         # Get the HatchMCP entry point (this handles both v1.2.0 and v1.2.1 schemas)
-        hatch_mcp_entry_point = package_service.get_hatch_mcp_entry_point()
-        if not hatch_mcp_entry_point:
+        mcp_entry_point = package_service.get_mcp_entry_point()
+        if not mcp_entry_point:
             raise ValueError(f"Package '{package_name}' does not have a HatchMCP entry point")
 
         # Get environment-specific Python executable
@@ -100,7 +100,7 @@ def get_package_mcp_server_config(env_manager: HatchEnvironmentManager, env_name
             python_executable = "python"
 
         # Create server configuration
-        server_path = str(package_path / hatch_mcp_entry_point)
+        server_path = str(package_path / mcp_entry_point)
         server_config = MCPServerConfig(
             name=package_name,
             command=python_executable,

tests/test_mcp_cli_package_management.py

@@ -267,15 +267,15 @@ def test_get_package_mcp_server_config_success(self):
             with patch('builtins.open', mock_open(read_data='{"package_schema_version": "1.2.1", "name": "test-package"}')):
                 with patch('hatch_validator.package.package_service.PackageService') as mock_service_class:
                     mock_service = MagicMock()
-                    mock_service.get_hatch_mcp_entry_point.return_value = "hatch_mcp_server.py"
+                    mock_service.get_mcp_entry_point.return_value = "mcp_server.py"
                     mock_service_class.return_value = mock_service
 
                     config = get_package_mcp_server_config(mock_env_manager, "test-env", "test-package")
 
                     self.assertIsInstance(config, MCPServerConfig)
                     self.assertEqual(config.name, "test-package")
                     self.assertEqual(config.command, "/path/to/python")  # Now uses environment-specific Python
-                    self.assertTrue(config.args[0].endswith("hatch_mcp_server.py"))
+                    self.assertTrue(config.args[0].endswith("mcp_server.py"))
 
     @regression_test
     def test_get_package_mcp_server_config_package_not_found(self):