Pressing ? replaced the entire TUI with the shortcut block: View() short-
circuited to renderKeybindingHelpOverlay, which centers the block on a blank
canvas, so the transcript, title bar, and composer all vanished. Every other
popup (model picker, suggestions, wizards) composites over the chat instead.
Route the help overlay through the SAME viewport-overlay path the pickers use:
add keybindingHelpOverlay(width) (returns "" when closed, else the centered
block) as the highest-priority case in transcriptView's overlay switch and in
twoColumnTranscriptView, and drop the content-replacement branch in View(). The
overlay now draws on top of the chat via the existing overlayViewportLines
compositing, keeping the transcript/title bar/composer visible behind it. Input
handling is unchanged — the modal key-swallow + ?/Esc/q/Enter dismiss run before
render — so only the presentation changes.
Tests: the help overlay composites over the chat chrome (title bar + composer
survive) and over a populated transcript row (red-green: with the old
full-replace both the chrome and the body are gone); existing
open/close/swallow/content tests unchanged.
Fixes#419
Gnanam
5746424272