ui(assets): move AI assistant to the bottom feedback position

src/components/Shell.tsx

@@ -165,7 +165,7 @@ export function Shell({ modules }: { modules: ModuleConfig[] }) {
         <Suspense fallback={<div className="p-3 md:p-6"><LoadingState label="正在加载业务模块" /></div>}>
           {ActiveComponent && <ActiveComponent />}
         </Suspense>
-        <FeedbackFab module={activeModule} />
+        {activeModule !== 'assets' && <FeedbackFab module={activeModule} />}
       </main>
 
       {/* 移动端底部导航 (md 以下) */}