[Bug Report] AppLauncher: Viewport mode broken: valid options use "omniverse" but logic checks "kit"

[jkkim-irim]

Environment

• Branch: dev/newton
• Commit: 5572031912eb2458e88eef67c716b9d41a6dc6ed

Summary

• Passing --visualizer kit causes Invalid visualizer(s) specified: ['kit'] and is rejected.
• Passing --visualizer omniverse passes validation but SimulationApp is not launched; the app runs in Standalone mode and the viewport is never enabled.

Root cause

• Validation (_resolve_visualizer_settings): valid_visualizers = ["rerun", "newton", "omniverse"] — "kit" is not allowed.
• Logic (_check_if_omniverse_required, _resolve_headless_settings): only "kit" in self._visualizer / "kit" in visualizers is checked — "omniverse" is never treated as viewport/SimulationApp.

So kit is rejected at input, and omniverse is accepted but does not trigger viewport/SimulationApp.