feat: 新增工作室展示开关 VITE_STUDIO_ENABLED

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend-web/src/components/workspace/workspace-nav-chat-list.tsx

@@ -19,6 +19,9 @@ import { BotIcon, BrainIcon, ListChecks, MessageSquarePlus, MessagesSquare, PenL
 import { SidebarCollapseButton } from "./workspace-header";
 import { WorkspaceNavStudio } from "./workspace-nav-studio";
 import { cn } from "@/lib/utils";
+import { env } from "@/env";
+
+const studioEnabled = env.STUDIO_ENABLED?.toLowerCase() === "true";
 
 // 普通导航项：默认中性色，激活态与「新对话」一致——主色浅底 + 主色文字/图标
 const NAV_ITEM_CLASS =
@@ -165,7 +168,7 @@ export function WorkspaceNavChatList({
         )}
       </SidebarMenu>
     </SidebarGroup>
-    {!showCollapseTrigger && <WorkspaceNavStudio />}
+    {!showCollapseTrigger && studioEnabled && <WorkspaceNavStudio />}
     </>
   );
 }