3c3a7cbbc1
Three Task 2 review findings: 1. The outside-click backdrop is a fixed full-viewport layer at z-index 1040, but the input-group was unpositioned — so once the panel was open a click on the field or the chevron hit the backdrop and closed the panel instead of letting the operator keep typing. The field now carries .ip-field (position:relative, z-index 1042), stacking backdrop < panel < field. Pinned in bUnit by the class (the z-index itself is scoped CSS, verified visually). 2. OnParametersSet closes the panel on ANY lists change, not only when the selection disappeared: an open panel is showing the previous site's tree, which is wrong even when the selected instance happens to exist in both. The reference-equality contract on Areas/Instances is now stated on both parameters — pass a stable reference, replace it only when the set changed. 3. Tests: the chevron closes an open panel; two pickers mint distinct panel ids (and matching aria-controls); an unrelated parameter change with the SAME Instances reference leaves a half-typed filter and the open panel alone. Claude-Session: https://claude.ai/code/session_01NcMG6xXdsJbmD2wYAgkK29