Maintainer/Codex found one narrow edge in the keyboard intent stamp: because the
listener runs capture-phase and accepts any focused descendant of #messages,
Space/Spacebar on an in-transcript control (tool-card toggles, copy buttons,
role buttons, links/tabs) stamped _lastMessageKeyScrollIntentMs before the
control handler could preventDefault/stopPropagation. That made a button
activation look like a scroll intent and could mask a legitimate post-render
artifact.
Fix by excluding Space/Spacebar when the event target or active element is an
interactive transcript control: button, a[href], select, summary, role=button,
role=tab, role=menuitem, or contenteditable. Keep PageUp/PageDown/arrows/Home/End
stamping unchanged, and keep the existing INPUT/TEXTAREA/contenteditable composer
exclusion.
Add a behavioral node-harness test: Space on a focused transcript button leaves
the key-scroll stamp at -Infinity (serialized null), while PageUp on the pane
still stamps 1234. test_4856 + test_4295 green (20 passed), node --check clean.
e2ea0789b3
