feat(web): Login/Register страницы, protected routes, logout

- ProtectedRoute: loading -> спиннер, !user -> /login, иначе children
- LoginPage/RegisterPage: field+react-hook-form/zod, ошибка через role=alert,
  редирект на /domains при успехе/уже авторизован
- main.tsx: AuthProvider + QueryCache/MutationCache onError -> notifyUnauthorized
  на UnauthorizedError (сброс сессии из кода вне React-дерева)
- AuthContext: logout и notifyUnauthorized чистят react-query кэш (qc.clear())
- Layout: email пользователя + кнопка Выйти
- App: /login и /register публичные (авторизованный -> /domains), остальное
  под ProtectedRoute

Починка page-тестов (Accounts/Domains/Templates/DomainDiff/App): AuthProvider
+ мок api.auth.me, спай-ассерты обновлены под projectId-первым-аргументом
сигнатур api.* (T5).

web/src/components/Layout.tsx

@@ -1,6 +1,8 @@
 import type { ReactNode } from "react"
-import { NavLink, useLocation } from "react-router-dom"
-import { Globe, Users, LayoutTemplate, SquareTerminal } from "lucide-react"
+import { NavLink, useLocation, useNavigate } from "react-router-dom"
+import { Globe, LogOut, Users, LayoutTemplate, SquareTerminal } from "lucide-react"
+import { useAuth } from "@/auth/AuthContext"
+import { Button } from "@/components/ui/button"
 import { cn } from "@/lib/utils"
 
 const NAV = [
@@ -11,6 +13,13 @@ const NAV = [
 
 export function Layout({ children }: { children: ReactNode }) {
   const location = useLocation()
+  const navigate = useNavigate()
+  const { user, logout } = useAuth()
+
+  async function onLogout() {
+    await logout()
+    navigate("/login", { replace: true })
+  }
 
   return (
     <div className="flex h-screen w-full overflow-hidden bg-background text-foreground">
@@ -64,10 +73,19 @@ export function Layout({ children }: { children: ReactNode }) {
       </aside>
 
       <div className="flex flex-1 flex-col overflow-hidden">
-        <header className="flex h-11 shrink-0 items-center border-b border-border px-6">
+        <header className="flex h-11 shrink-0 items-center justify-between border-b border-border px-6">
           <span className="font-dns text-xs text-muted-foreground">
             {location.pathname}
           </span>
+          {user && (
+            <div className="flex items-center gap-3">
+              <span className="font-dns text-xs text-muted-foreground">{user.email}</span>
+              <Button variant="ghost" size="sm" onClick={onLogout}>
+                <LogOut className="size-3.5" strokeWidth={1.75} />
+                Выйти
+              </Button>
+            </div>
+          )}
         </header>
         <main className="flex-1 overflow-auto">{children}</main>
       </div>