How a developer actually reaches the diagnostic panel: right-click the face, or press Ctrl/Cmd+Shift+D. It owns everything the panel deliberately does not — whether the panel may be shown at all, the context menu (Open diagnostics / Copy runtime report / Reset counters), the resizable drawer docked right or bottom, the per-viewer tab and placement preferences, and the session's open/close lifecycle, so a closed panel costs nothing on the audio thread. The drawer is portalled into the face surface and absolutely positioned, so opening it never reflows the face. Right-clicks on text-editing islands, on module-owned [data-context-menu="browser"] targets and inside nested module context menus keep their own menu.
pnpm dlx shadcn@latest add "https://pluginui.com/r/core-diagnostic-overlay.json"