Integrate project classroom with teacher and friend consultations

src/components/layout/TitleBar.tsx

@@ -79,12 +79,9 @@ function ProductTitleBar({
   };
   // The project sidebar preview is rendered below the title bar, so mirror
   // its full width in the title bar for ordinary pages. The chat workspace
-  // has an independent conversation rail and must keep its pinned columns.
+  // keeps project conversations in the sidebar and must preserve its title rail.
   const sidebarPreviewTitlebarVisible = sidebarCollapsed && sidebarPeekOpen && !workspaceLayout && !overlay;
   const sidebarTitlebarHidden = sidebarCollapsed && !sidebarPreviewTitlebarVisible;
-  const conversationSurfaceOffset = sidebarTitlebarHidden
-    ? (nativeTrafficLights ? '-132px' : '-52px')
-    : '0px';
   const sidebarToggle = (
     <button
       type="button"
@@ -194,13 +191,6 @@ function ProductTitleBar({
             marginRight: 'var(--agent-browser-panel-width, 0px)',
           }}
         >
-          {workspaceLayout ? (
-            <div
-              data-testid="titlebar-conversation-surface"
-              className="pointer-events-none absolute inset-y-0 z-0 w-[256px] border-r border-border/80 bg-surface-tertiary"
-              style={{ left: conversationSurfaceOffset }}
-            />
-          ) : null}
           {pageTitle ? (
             <h1
               data-testid="titlebar-page-title"
@@ -219,7 +209,7 @@ function ProductTitleBar({
               <span className="truncate text-sm font-semibold">{activeProject?.name ?? 'Makelore 工作台'}</span>
             </div>
           ) : null}
-          {!overlay ? titlebarLogo : null}
+          {!overlay && !workspaceLayout ? titlebarLogo : null}
           <div
             className={cn(
               'no-drag absolute inset-y-0 right-0 z-10 flex items-center justify-end gap-1 px-2',