fix: isolate concurrent OpenCode chat runs

tests/unit/provider-store-validation.test.ts

@@ -217,7 +217,51 @@ describe('useProviderStore importUserModelConfig()', () => {
     expect(result.importedModels).toEqual(['gpt-4.1-mini', 'gpt-4o-mini']);
     expect(mockHostApiFetch).toHaveBeenCalledWith('/api/provider-accounts/import-user-model-config', {
       method: 'POST',
-      body: JSON.stringify({ accessToken: 'access-token' }),
+      body: JSON.stringify({
+        accessToken: 'access-token',
+        runtimeRefresh: 'apply',
+      }),
+    });
+    expect(mockFetchProviderSnapshot).toHaveBeenCalledOnce();
+  });
+
+  it('defers runtime refresh when requested and exposes whether a manual restart is required', async () => {
+    const account = {
+      id: 'niancode-user-models',
+      vendorId: 'custom',
+      label: 'Makelore Models',
+      authMode: 'api_key',
+      model: 'gpt-4.1-mini',
+      enabled: true,
+      isDefault: true,
+      createdAt: '2026-06-19T00:00:00.000Z',
+      updatedAt: '2026-06-19T00:00:00.000Z',
+    } as const;
+    mockHostApiFetch.mockResolvedValueOnce({
+      success: true,
+      account,
+      importedModels: ['gpt-4.1-mini'],
+      runtimeRefreshRequired: true,
+    });
+    mockFetchProviderSnapshot.mockResolvedValueOnce({
+      statuses: [],
+      accounts: [account],
+      vendors: [],
+      defaultAccountId: account.id,
+    });
+
+    const result = await useProviderStore.getState().importUserModelConfig(
+      'access-token',
+      { runtimeRefresh: 'defer' },
+    );
+
+    expect(result.runtimeRefreshRequired).toBe(true);
+    expect(mockHostApiFetch).toHaveBeenCalledWith('/api/provider-accounts/import-user-model-config', {
+      method: 'POST',
+      body: JSON.stringify({
+        accessToken: 'access-token',
+        runtimeRefresh: 'defer',
+      }),
     });
     expect(mockFetchProviderSnapshot).toHaveBeenCalledOnce();
   });