The floating chat window covered page content; you could only collapse it
manually. Now it auto-collapses to its header (visual collapse only — ChatThread
stays mounted so an in-flight stream isn't interrupted) when you interact with
the page, and expands again from the header.
- document mousedown listener in the CAPTURE phase, armed only when
windowOpen && !minimized; collapses on a pointer-down outside the window.
Guards: ignore clicks inside the window and inside any Mantine [data-portal]
(the chat-list kebab menu + delete-confirm modal render in portals).
- Header click expands: startDrag distinguishes click vs drag by a 4px
threshold (minimizedRef avoids a stale closure); an expand-click doesn't
persist geometry.
- Reset minimized=false when the window opens (no sticky collapsed state).
- a11y: when minimized, the title is the keyboard expand affordance
(role=button, tabIndex, aria-label Expand, Enter/Space) — kept off the
dragBar container so no role=button wraps the Minimize/Close buttons.
- Pure helpers shouldCollapseOnOutsidePointer + isHeaderClick with vitest tests.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
