fix(ui): restore searchable credential model picker

Use each credential's model IDs in the model name field and filter matches while typing.

Fixes #

tests/credentialAliasPicker.test.tsx

@@ -5,19 +5,18 @@ import { I18nProvider } from '../src/i18n';
 
 const html = renderToStaticMarkup(
   <I18nProvider>
-    <CredentialAdvancedFields name="codex-user.json" advanced={{ model_aliases: [{ name: 'gpt-5', alias: 'public-gpt' }] }} onChange={() => {}} />
+    <CredentialAdvancedFields name="codex-user.json" advanced={{ model_aliases: [{ name: 'gpt-5', alias: 'public-gpt' }] }}
+      models={[{ name: 'gpt-5', alias: 'GPT 5' }]} onChange={() => {}} />
   </I18nProvider>,
 );
 
-describe('credential alias editor', () => {
-  it('uses plain inputs for the upstream model and client alias', () => {
-    expect(html).not.toContain('role="combobox"');
+describe('credential alias model picker', () => {
+  it('uses the credential model list for the upstream model and a plain input for the alias', () => {
+    expect(html.match(/role="combobox"/g)).toHaveLength(1);
     expect(html).toContain('aria-label="Model name"');
     expect(html).toContain('aria-label="Model alias"');
     expect(html).toContain('value="gpt-5"');
     expect(html).toContain('value="public-gpt"');
-    expect(html).toContain('aria-label="Expand"');
-    expect(html).not.toContain('Display name');
-    expect(html).not.toContain('Search or enter a model');
+    expect(html).toContain('Search or enter a model');
   });
 });