fix(models): keep manual creation available on catalog failure

frontend/src/features/models/components/GlobalModelFormDialog.vue

@@ -63,6 +63,16 @@
               <RefreshCw class="h-3.5 w-3.5" />
               重试
             </Button>
+            <Button
+              type="button"
+              variant="ghost"
+              size="sm"
+              class="h-8"
+              data-testid="models-catalog-manual-entry"
+              @click="enterManualEntryMode"
+            >
+              直接手动填写
+            </Button>
           </div>
           <template v-else>
             <!-- 提供商 Logo 横向选择 -->

frontend/src/features/models/components/__tests__/GlobalModelFormDialog.prefill.spec.ts

@@ -279,6 +279,29 @@ describe('GlobalModelFormDialog preset replacement', () => {
     expect(document.body.textContent).toContain('Fresh Model')
   })
 
+  it('keeps manual model creation available when the external catalog is unavailable', async () => {
+    modelsDevMocks.getModelsDevList.mockRejectedValueOnce({
+      response: {
+        status: 503,
+        data: { detail: 'External models catalog unavailable' },
+      },
+    })
+
+    mountDialog()
+    await settle()
+
+    const manualEntryButton = document.body.querySelector<HTMLButtonElement>(
+      '[data-testid="models-catalog-manual-entry"]',
+    )
+    if (!manualEntryButton) throw new Error('Missing catalog manual-entry button')
+    manualEntryButton.click()
+    await settle()
+
+    expect(document.body.querySelector('[data-testid="models-catalog-load-error"]')).toBeNull()
+    expect(document.body.textContent).toContain('手动填写模式')
+    expect(document.body.querySelector('#model-name')).not.toBeNull()
+  })
+
   it('drops the previous draft and submits only the newly selected model preset', async () => {
     mountDialog()
     await settle()