frontend: normalize auth oauth i18n and error toasts

frontend/src/views/auth/__tests__/WechatCallbackView.spec.ts

@@ -71,6 +71,9 @@ vi.mock('vue-i18n', () => ({
   }),
   useI18n: () => ({
     t: (key: string, params?: Record<string, string>) => {
+      if (key === 'auth.oauthFlow.totpHint') {
+        return `verify ${params?.account ?? ''}`.trim()
+      }
       if (key === 'auth.oidc.callbackTitle') {
         return `Signing you in with ${params?.providerName ?? ''}`.trim()
       }
@@ -695,6 +698,34 @@ describe('WechatCallbackView', () => {
     )
   })
 
+  it('shows create-account failures through toast without inline error text', async () => {
+    exchangePendingOAuthCompletionMock.mockResolvedValue({
+      error: 'email_required',
+      redirect: '/welcome',
+    })
+    apiClientPostMock.mockRejectedValue(new Error('create failed'))
+
+    const wrapper = mount(WechatCallbackView, {
+      global: {
+        stubs: {
+          AuthLayout: { template: '<div><slot /></div>' },
+          Icon: true,
+          RouterLink: { template: '<a><slot /></a>' },
+          transition: false,
+        },
+      },
+    })
+
+    await flushPromises()
+    await wrapper.get('[data-testid="wechat-create-account-email"]').setValue('new@example.com')
+    await wrapper.get('[data-testid="wechat-create-account-password"]').setValue('secret-123')
+    await wrapper.get('[data-testid="wechat-create-account-submit"]').trigger('click')
+    await flushPromises()
+
+    expect(showErrorMock).toHaveBeenCalledWith('create failed')
+    expect(wrapper.text()).not.toContain('create failed')
+  })
+
   it('sends a verify code for pending oauth account creation', async () => {
     exchangePendingOAuthCompletionMock.mockResolvedValue({
       error: 'email_required',