test: add filterwarnings and fix remaining unawaited coroutine

- Add filterwarnings = ["error::RuntimeWarning"] to pyproject.toml
  to promote unawaited coroutine warnings to hard test failures
- Fix one additional unawaited coroutine in test_sets_media_theme
  where mocked _run_command discarded write_parameters coroutine

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: deviantintegral

pyproject.toml

@@ -51,6 +51,7 @@ strict = true
 [tool.pytest.ini_options]
 asyncio_mode = "auto"
 testpaths = ["tests"]
+filterwarnings = ["error::RuntimeWarning"]
 
 [tool.coverage.run]
 source = ["src/flameconnect"]

tests/test_tui_actions.py

@@ -825,6 +825,7 @@ async def test_sets_media_theme(self, mock_client, mock_dashboard):
         call_args = app._run_command.call_args
         assert call_args[0][1] == "Setting media theme to Blue..."
         assert call_args[0][2] == "Media theme change failed"
+        call_args[0][0].close()
 
     async def test_no_op_when_write_in_progress(self, mock_client, mock_dashboard):
         app = _make_app(mock_client, mock_dashboard)