refactor(ui): remove Cmd+B sidebar toggle keyboard shortcut

Co-authored-by: multica-agent <github@multica.ai>

packages/views/layout/app-sidebar.tsx

@@ -51,6 +51,7 @@ import {
   SidebarMenuButton,
   SidebarMenuItem,
   SidebarRail,
+  SidebarTrigger,
 } from "@multica/ui/components/ui/sidebar";
 import {
   DropdownMenu,
@@ -691,7 +692,8 @@ export function AppSidebar({ topSlot, searchSlot, headerClassName, headerStyle }
         </SidebarContent>
 
         <SidebarFooter className="p-2">
-          <div className="flex justify-end">
+          <div className="flex items-center justify-between">
+            <SidebarTrigger />
             <HelpLauncher />
           </div>
         </SidebarFooter>

packages/views/layout/page-header.tsx

@@ -3,13 +3,14 @@
 import { cn } from "@multica/ui/lib/utils";
 import { SidebarTrigger, useSidebar } from "@multica/ui/components/ui/sidebar";
 
-function MobileSidebarTrigger() {
+function SidebarToggle() {
   try {
-    useSidebar();
+    const { state } = useSidebar();
+    // On mobile: always show (hamburger). On desktop: only when sidebar is collapsed.
+    return <SidebarTrigger className={cn("mr-2", state === "expanded" && "md:hidden")} />;
   } catch {
     return null;
   }
-  return <SidebarTrigger className="mr-2 md:hidden" />;
 }
 
 interface PageHeaderProps {
@@ -20,7 +21,7 @@ interface PageHeaderProps {
 export function PageHeader({ children, className }: PageHeaderProps) {
   return (
     <div className={cn("flex h-12 shrink-0 items-center border-b px-4", className)}>
-      <MobileSidebarTrigger />
+      <SidebarToggle />
       {children}
     </div>
   );