Esc over a mermaid focus, the plan popup, or the setup dialog opened the
question-dismiss confirm underneath — KeyboardShortcuts' window listener
registers first, so the overlays' own self-closing Esc listeners could
never outrun the lh:kbd-abort-turn dispatch. The state gate in ChatView
is the defense (the architecture's own pattern from the abort dialog):
escAbortTarget, exported pure, rules priority by stacking order — abort
confirm (claimed by its dialog) > mermaid (paints above plan) > plan >
setup (self-closing) > question > turn. The gate closes the overlay; the
overlays' own listeners stay (idempotent). Pinned in esc-layering.test.
