feat: inherit model-picker reorder/accordion persistence and shift-delete from otto-ui (#1833)

* feat(model-picker): drag-to-reorder providers and persist accordion state

Ports two model/provider picker QoL features from otto-ui:
- Persist collapsed state of picker sections (favorites, recent, each
  provider) via a new persisted zustand store so collapse survives
  remounts and reloads, shared across every picker surface.
- Desktop drag-to-reorder of provider sections (whole header as the
  mouse activator, 8px threshold so a plain click still toggles
  collapse), with the order persisted in useUIStore.providerOrder and
  applied across ModelControls, ModelMultiSelect and ModelSelector.

Co-authored-by: Serhii Dziupin <makeittech@users.noreply.github.com>

* feat(sessions): shift-click quick action hard-deletes thread without prompt

Ports the shift-quick-delete feature from otto-ui. The sidebar quick
action (normally archive) becomes a no-prompt hard delete while Shift is
held: the icon switches to a trash bin, the affordance turns destructive,
and the click bypasses the confirmation dialog via a new skipConfirm
source flag. A shared useShiftKeyHeld hook (single window listener set,
useSyncExternalStore) keeps only the small action button re-rendering on
Shift state changes, and resets on window blur so the affordance can't
get stuck after alt-tab.

Co-authored-by: Serhii Dziupin <makeittech@users.noreply.github.com>

---------

Co-authored-by: Serhii Dziupin <makeittech@users.noreply.github.com>

packages/ui/src/components/multirun/ModelMultiSelect.tsx

@@ -107,6 +107,7 @@ export const ModelMultiSelect: React.FC<ModelMultiSelectProps> = ({
   const isFavoriteModel = useUIStore((state) => state.isFavoriteModel);
   const { favoriteModelsList, recentModelsList } = useModelLists();
   const hiddenModels = useUIStore((state) => state.hiddenModels);
+  const providerOrder = useUIStore((state) => state.providerOrder);
   const [isOpen, setIsOpen] = React.useState(false);
   const [searchQuery, setSearchQuery] = React.useState('');
   const [availableHeight, setAvailableHeight] = React.useState<number | null>(null);
@@ -260,6 +261,7 @@ export const ModelMultiSelect: React.FC<ModelMultiSelectProps> = ({
             >
               <ModelPickerList
                 providers={providers}
+                providerOrder={providerOrder}
                 favoriteModels={favoriteModelsList}
                 recentModels={recentModelsList}
                 modelsMetadata={modelsMetadata}