Corporate Tools is the first PCDetail tab that mounts no PluginAssetPanels: it is permission-gated and renders a fixed action list, so no panel can land in it. The vocabulary check asserted every tabs.push key appears in RENDERED_GROUPS, which cd70556 broke by adding that tab.
Adding 'corptools' to the vocabulary would have made it a legal panel group with no panel host - fetched, held, rendered nowhere - the silent-drop failure this file exists to catch, and it would also have failed the server-vocabulary check against ASSET_PANEL_GROUPS. So the invariant is narrowed to panel-backed tabs instead, with a mirror check that any tab mounting a PluginAssetPanels must have its group rendered.
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