tui: fix sidebar background color when collapsed

When the sidebar was collapsed (not on mobile), the background color was showing as the stronger variant instead of matching the base background. This fixes the hover state detection so users see a consistent lighter background when the sidebar is in collapsed mode.

packages/app/src/pages/layout.tsx

@@ -1891,6 +1891,7 @@ export default function Layout(props: ParentProps) {
 
   const SidebarPanel = (panelProps: { project: LocalProject | undefined; mobile?: boolean; merged?: boolean }) => {
     const merged = createMemo(() => panelProps.mobile || (panelProps.merged ?? layout.sidebar.opened()))
+    const hover = createMemo(() => !panelProps.mobile && panelProps.merged === false && !layout.sidebar.opened())
     const projectName = createMemo(() => {
       const project = panelProps.project
       if (!project) return ""
@@ -1919,8 +1920,8 @@ export default function Layout(props: ParentProps) {
           "flex flex-col min-h-0 min-w-0 rounded-tl-[12px] px-2": true,
           "border border-b-0 border-border-weak-base": !merged(),
           "border-l border-t border-border-weaker-base": merged(),
-          "bg-background-base": merged(),
-          "bg-background-stronger": !merged(),
+          "bg-background-base": merged() || hover(),
+          "bg-background-stronger": !merged() && !hover(),
           "flex-1 min-w-0": panelProps.mobile,
           "max-w-full overflow-hidden": panelProps.mobile,
         }}