* fix(app): keep provider settings above model selector
Desktop web comboboxes used the browser top layer, so ordinary modal portals could not cover them. Keep web overlays in one relative layer stack while preserving native bottom-sheet stacking.
* fix(app): route overlay keyboard ownership
* fix(app): preserve nested overlay ownership
* fix(app): route command center overlay input
* fix(app): preserve global overlay ancestry
* fix(app): register global dialog hosts
Provider settings sheets can remain mounted while hidden, so the old display cache could survive into a different provider. Scope the cache to the active provider identity and remount the sheet when that identity changes.
Surface all enabled providers in the model selector with inline loading
and error states instead of silently hiding non-ready ones. Tap any row
to drill in; loading and error states show in the drill-down body, with
a Retry button on error. Providers with no models render a synthetic
"Default" row so every provider's drill-down has symmetric structure.
Redesign the per-provider settings sheet: search lives in the header,
discovered and custom models share one scrolling list, and the footer
hosts action buttons. Diagnostic and "Add model" each open as their own
sub-sheet, so neither expands inline or shifts the surrounding layout.
Snapshot refresh now keeps cached data visible: setQueryData replaces
the cache atomically and sibling-scope caches are invalidated (not
removed), so refreshing a provider no longer blanks its row. Search
inputs across the app are uncontrolled — onChangeText drives parent
state, and resetKey remounts the field when an explicit reset is needed
— to avoid RN's controlled-input flicker.
Adds a dev-only mock-slow provider whose discovery never resolves, so
the 30s snapshot timeout produces a real error and lets loading and
timeout-error UI be exercised end to end.
