Both the sidebar and the full-pane chat composers hand-rolled the same
LayerLink + OverlayEntry + _showOverlay/_removeOverlay + _AtOverlay. Replace
both with ClideTypeahead driven by the suggestion list; delete _AtOverlay and
the per-copy overlay plumbing. The text parsing/completion (activeAtQuery,
filterAtNames, completeAt, parseAtTag) and the Esc handler stay in the hosts.
Behaviour is unchanged (the popover now uses the shared dropdown styling);
team_chat_sidebar_test stays green.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
jpmschweitzerandClaude Opus 4.8
60312eff3b