GRM-16: test: add molecule lifecycle scenarios, integration tests, and docs

- Add multi-instance molecule scenario verifying isolated data/config dirs
- Add lifecycle molecule scenario testing stop/disable/enable/start sequence
- Update default and binary verify playbooks for template unit assertions
- Add integration tests for full CLI lifecycle and multi-instance support
- Add pytest integration marker and --no-cov Makefile target
- Update README with lifecycle commands, multi-instance examples, and architecture
- Update Makefile with start/stop/enable/disable/status/remove targets
- Update .env.example with GRM_LANG documentation

tests/integration/test_multi_instance.py

@@ -0,0 +1,55 @@
+"""Integration tests for multi-instance support."""
+
+from unittest.mock import MagicMock, patch
+
+import pytest
+from click.testing import CliRunner
+
+from gitea_runner_manager.cli import cli
+
+
+@pytest.mark.integration
+class TestMultiInstanceCLI:
+    """Test that multiple runner instances can be managed independently."""
+
+    @patch("gitea_runner_manager.cli.RunnerManager")
+    def test_install_two_instances(self, mock_manager_class: MagicMock) -> None:
+        """Install two named instances on the same host."""
+        mock_manager = MagicMock()
+        mock_manager_class.return_value = mock_manager
+
+        env = {"GITEA_URL": "https://git.example.com", "GITEA_REGISTRATION_TOKEN": "tok"}
+        runner = CliRunner(env=env)
+
+        # Install instance A
+        result = runner.invoke(cli, ["install", "host1", "--user", "ubuntu", "--name", "runner-a"])
+        assert result.exit_code == 0
+
+        # Install instance B
+        result = runner.invoke(cli, ["install", "host1", "--user", "ubuntu", "--name", "runner-b", "--mode", "binary"])
+        assert result.exit_code == 0
+
+        assert mock_manager.install.call_count == 2
+        calls = mock_manager.install.call_args_list
+        assert calls[0].kwargs["name"] == "runner-a"
+        assert calls[0].kwargs["mode"] == "docker"
+        assert calls[1].kwargs["name"] == "runner-b"
+        assert calls[1].kwargs["mode"] == "binary"
+
+    @patch("gitea_runner_manager.cli.RunnerManager")
+    def test_start_stop_one_instance(self, mock_manager_class: MagicMock) -> None:
+        """Start one instance and stop another independently."""
+        mock_manager = MagicMock()
+        mock_manager_class.return_value = mock_manager
+
+        runner = CliRunner()
+
+        result = runner.invoke(cli, ["start", "host1", "--user", "ubuntu", "--name", "runner-a"])
+        assert result.exit_code == 0
+        mock_manager.start.assert_called_once_with(
+            host="host1", user="ubuntu", name="runner-a", mode="docker", ask_become_pass=False
+        )
+
+        result = runner.invoke(cli, ["stop", "host1", "--user", "ubuntu", "--name", "runner-b"])
+        assert result.exit_code == 0
+        mock_manager.stop.assert_called_once_with(host="host1", user="ubuntu", name="runner-b", ask_become_pass=False)