feat(web): assemble header — breadcrumb, search, user menu; remove standalone sign out (#54)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

web/src/shell/app-shell.tsx

@@ -1,24 +1,14 @@
-import { Outlet, useNavigate } from "react-router-dom";
-import { useTranslation } from "react-i18next";
+import { Outlet } from "react-router-dom";
 
-import { useLogout } from "../api/queries";
-import { Button } from "@/components/ui/button";
 import { LangSwitch } from "./lang-switch";
 import { ThemeSwitch } from "./theme-switch";
 import { Sidebar } from "./sidebar";
 import { BreadcrumbProvider } from "./breadcrumb-provider";
 import { Breadcrumb } from "./breadcrumb";
+import { HeaderSearch } from "./header-search";
+import { UserMenu } from "./user-menu";
 
 export function AppShell() {
-  const { t } = useTranslation();
-  const navigate = useNavigate();
-  const logout = useLogout();
-
-  const onSignOut = () =>
-    logout.mutate(undefined, {
-      onSuccess: () => navigate("/login", { replace: true }),
-    });
-
   return (
     <div className="flex min-h-screen">
       <Sidebar />
@@ -26,11 +16,10 @@ export function AppShell() {
         <div className="flex flex-1 flex-col">
           <header className="flex items-center gap-4 border-b px-4 py-2">
             <Breadcrumb />
+            <HeaderSearch />
             <ThemeSwitch />
             <LangSwitch />
-            <Button variant="ghost" size="sm" onClick={onSignOut}>
-              {t("auth.signOut")}
-            </Button>
+            <UserMenu />
           </header>
           <main className="flex-1 overflow-hidden">
             <Outlet />