feat: enhance settings navigation with collapsible sub-items and local storage state

- Implemented a collapsible dropdown for navigation items in the settings view, allowing users to expand or collapse sub-items.
- Added local storage functionality to remember the open/closed state of the dropdown across sessions.
- Updated the styling and interaction logic for improved user experience and accessibility.

These changes improve the organization of navigation items and enhance user interaction within the settings view.

apps/ui/src/components/views/settings-view/model-defaults/phase-model-selector.tsx

@@ -876,7 +876,13 @@ export function PhaseModelSelector({
       className="w-[320px] p-0"
       align={align}
       onWheel={(e) => e.stopPropagation()}
-      onPointerDownOutside={(e) => e.preventDefault()}
+      onPointerDownOutside={(e) => {
+        // Only prevent close if clicking inside a nested popover (thinking level panel)
+        const target = e.target as HTMLElement;
+        if (target.closest('[data-slot="popover-content"]')) {
+          e.preventDefault();
+        }
+      }}
     >
       <Command>
         <CommandInput placeholder="Search models..." />