fix(chat): clear translation memory + worker on logout

Translations are memory-only; on logout/account switch we now clear the cache,
reject pending requests and terminate the worker (the model itself is public
and stays in the browser cache).

src/components/Layout.tsx

@@ -16,6 +16,7 @@ import {
 import { LoginArea } from '@/components/auth/LoginArea';
 import { useSasquatchGuide } from '@/hooks/useSasquatchGuide';
 import { LanguageToggle } from '@/components/LanguageToggle';
+import { clearTranslationMemory } from '@/lib/translation';
 import { useCurrentUser } from '@/hooks/useCurrentUser';
 import { useTranslation } from '@/contexts/language';
 import { useLoggedInAccounts } from '@/hooks/useLoggedInAccounts';
@@ -812,7 +813,7 @@ export function Layout({ children, noPadding }: LayoutProps) {
             {user && (
               <MobileHeaderUserMenu
                 pubkey={user.pubkey}
-                onLogout={() => removeLogin(currentAccount?.id || '')}
+                onLogout={() => { clearTranslationMemory(); removeLogin(currentAccount?.id || ''); }}
                 onSetStatus={() => setShowStatusDialog(true)}
                 onAddAccount={() => setShowAddAccount(true)}
               />
@@ -1038,6 +1039,7 @@ export function Layout({ children, noPadding }: LayoutProps) {
                           size="lg"
                           className="w-full justify-center gap-3 text-red-400 border-red-500/50 hover:bg-red-500/20 hover:text-red-300 hover:border-red-500 h-12 text-base font-bold"
                           onClick={() => {
+                            clearTranslationMemory();
                             removeLogin(currentAccount?.id || '');
                             setMobileMenuOpen(false);
                           }}

src/components/auth/AccountSwitcher.tsx

@@ -12,6 +12,7 @@ import {
 import { Avatar, AvatarFallback, AvatarImage } from '@/components/ui/avatar.tsx';
 import { WalletModal } from '@/components/WalletModal';
 import { clearDmDecryptCache } from '@/lib/dmDecryptCache';
+import { clearTranslationMemory } from '@/lib/translation';
 import { useLoggedInAccounts, type Account } from '@/hooks/useLoggedInAccounts';
 import { genUserName } from '@/lib/genUserName';
 import { useTranslation } from '@/contexts/language';
@@ -102,6 +103,7 @@ export function AccountSwitcher({ onAddAccountClick }: AccountSwitcherProps) {
             // Drop this account's plaintext DM cache (device-local) on logout so
             // another account on the same device can't read it from IndexedDB.
             void clearDmDecryptCache(currentUser.id).catch(() => {});
+            clearTranslationMemory();
             removeLogin(currentUser.id);
           }}
           className='flex items-center gap-2 cursor-pointer p-2 rounded-md text-red-500'

src/lib/translation.ts

@@ -145,4 +145,9 @@ export async function translateText(params: TranslateParams): Promise<string> {
 /** Clear the in-memory translation cache (e.g. on logout). */
 export function clearTranslationMemory(): void {
   memoryCache.clear();
+  rejectAll(new Error('CLEARED'));
+  if (worker) {
+    worker.terminate();
+    worker = null;
+  }
 }