Rapid pointer changes repeatedly restarted inherited color transitions in both presentation menu levels. Disable transitions on these rows while preserving focus and submenu behavior. Previous coverage checked open state only; the browser regression now compares next-frame highlight colors against the theme and fails with the old transition restored.
Also verify header timeline hide/restore after expansion at 320, 375, 1024 and 1440 pixels.
Validation: lint, typecheck, 1178 unit tests, five focused browser cases and production build passed.
Group adjacent live display steps into category menus with merged snapshots, original-step submenus and scoped playback.
The submenu exposes the latest raw step, so explicit selections must remain pinned. Locate failed and cancelled steps using the full group sequence, and prevent an exiting menu from dismissing a trigger-owned reopen. Regression tests reproduce these paths before the fixes.
Validation: lint, typecheck, 1178 unit tests and 10 focused browser cases passed; update the presentation history guide.
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