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/main.tsx

@@ -4,18 +4,35 @@ import "@fontsource/ibm-plex-mono/500.css"
 import "./index.css"
 import React from "react"
 import ReactDOM from "react-dom/client"
-import { QueryClient, QueryClientProvider } from "@tanstack/react-query"
+import { QueryCache, QueryClient, QueryClientProvider, MutationCache } from "@tanstack/react-query"
 import { BrowserRouter } from "react-router-dom"
+import { UnauthorizedError } from "@/api/client"
+import { AuthProvider, notifyUnauthorized } from "@/auth/AuthContext"
 import { App } from "./App"
 
-const queryClient = new QueryClient()
+// A 401 from *any* query or mutation means the session died server-side
+// (expired/destroyed cookie) — drop it from here rather than requiring every
+// hook in useApi.ts to remember to handle it individually. AuthContext reacts
+// via notifyUnauthorized (registered by AuthProvider), which resets
+// user/project and clears the cache; ProtectedRoute then redirects to
+// /login on the next render.
+function onQueryError(error: unknown) {
+  if (error instanceof UnauthorizedError) notifyUnauthorized()
+}
+
+const queryClient = new QueryClient({
+  queryCache: new QueryCache({ onError: onQueryError }),
+  mutationCache: new MutationCache({ onError: onQueryError }),
+})
 
 ReactDOM.createRoot(document.getElementById("root")!).render(
   <React.StrictMode>
     <QueryClientProvider client={queryClient}>
-      <BrowserRouter>
-        <App />
-      </BrowserRouter>
+      <AuthProvider>
+        <BrowserRouter>
+          <App />
+        </BrowserRouter>
+      </AuthProvider>
     </QueryClientProvider>
   </React.StrictMode>,
 )