fix(desktop): resync fallback editor after config reload

apps/desktop/src/app/settings/fallback-models-field.test.tsx

@@ -43,6 +43,23 @@ async function renderField(value: unknown, onChange = vi.fn()) {
   return onChange
 }
 
+async function renderFieldWithRerender(value: unknown, onChange = vi.fn()) {
+  const { FallbackModelsField } = await import('./fallback-models-field')
+  const client = new QueryClient({ defaultOptions: { queries: { retry: false } } })
+  const view = render(
+    <QueryClientProvider client={client}>
+      <FallbackModelsField onChange={onChange} value={value} />
+    </QueryClientProvider>
+  )
+
+  return (next: unknown) =>
+    view.rerender(
+      <QueryClientProvider client={client}>
+        <FallbackModelsField onChange={onChange} value={next} />
+      </QueryClientProvider>
+    )
+}
+
 const CHAIN = [
   { provider: 'copilot', model: 'gpt-5-mini' },
   { provider: 'openai-codex', model: 'gpt-5.4-mini' }
@@ -84,4 +101,13 @@ describe('FallbackModelsField', () => {
     expect(screen.getByText(/No fallback models/)).toBeTruthy()
     expect(screen.queryAllByLabelText('Remove')).toHaveLength(0)
   })
+
+  it('resyncs rows when persisted config changes', async () => {
+    const rerender = await renderFieldWithRerender(CHAIN)
+    expect(screen.getAllByLabelText('Remove')).toHaveLength(2)
+
+    rerender([{ provider: 'nous', model: 'hermes-4' }])
+
+    await waitFor(() => expect(screen.getAllByLabelText('Remove')).toHaveLength(1))
+  })
 })

apps/desktop/src/app/settings/fallback-models-field.tsx

@@ -1,5 +1,5 @@
 import { useQuery } from '@tanstack/react-query'
-import { useState } from 'react'
+import { useEffect, useState } from 'react'
 
 import { Button } from '@/components/ui/button'
 import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from '@/components/ui/select'
@@ -70,6 +70,12 @@ export function FallbackModelsField({
 
   const [rows, setRows] = useState<FallbackEntry[]>(() => normalizeEntries(value))
 
+  // Settings can reload after a profile/config change while this component
+  // stays mounted. Avoid displaying or saving the previous profile's chain.
+  useEffect(() => {
+    setRows(normalizeEntries(value))
+  }, [value])
+
   const commit = (next: FallbackEntry[]) => {
     setRows(next)
     onChange(next.filter(entry => entry.provider && entry.model))