feat: integrate pinned teacher discussion workspace

src/components/layout/Sidebar.tsx

@@ -9,6 +9,7 @@ import {
   Cpu,
   ChevronRight,
   FolderKanban,
+  Gamepad2,
   LogOut,
   Plus,
   RadioTower,
@@ -476,7 +477,7 @@ export function Sidebar({
                         : 'bg-transparent text-foreground hover:bg-surface-tertiary',
                     )}
                   >
-                    <FolderKanban className="h-3.5 w-3.5 shrink-0 text-muted-foreground" /><span className="min-w-0 flex-1 truncate text-[13px] font-medium">{project.name}</span>
+                    <Gamepad2 className="h-3.5 w-3.5 shrink-0 text-muted-foreground" /><span className="min-w-0 flex-1 truncate text-[13px] font-medium">{project.name}</span>
                     <ChevronRight aria-hidden="true" className="h-3.5 w-3.5 shrink-0 -translate-x-0.5 text-muted-foreground opacity-50 transition-[opacity,transform,color] duration-200 ease-out group-hover/project:translate-x-0 group-hover/project:text-foreground group-hover/project:opacity-100 group-focus-visible/project:translate-x-0 group-focus-visible/project:text-foreground group-focus-visible/project:opacity-100" />
                   </button>
                   {active && <CodingProjectConversations key={project.id} projectId={project.id} compact={workspaceLayout} />}