Fix CLI test compatibility across Python versions

Fix tests/test_cli.py::TestCLI::test_cli_no_command for Python 3.8/3.9 compatibility.

Click behavior varies between versions:
- Python 3.10+: Returns exit code 2 when no command given
- Python 3.8/3.9: Returns exit code 0 when no command given

Updated test to accept both exit codes [0, 2] while still verifying
that help text is displayed correctly.

Resolves GitHub Actions test failures on Python 3.8 and 3.9 matrices.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: jeremymanning

tests/test_cli.py

@@ -186,5 +186,6 @@ def test_status_connection_failed(
     def test_cli_no_command(self, runner):
         """Test CLI with no command shows help."""
         result = runner.invoke(cli, [])
-        assert result.exit_code == 2  # Click returns 2 when no command is given
+        # Click behavior varies by version: may return 0 or 2 when no command is given
+        assert result.exit_code in [0, 2]
         assert "Clustrix CLI" in result.output