fix(webui): keep schema defaults out of model presets

webui/src/components/settings/models/ModelsSettings.tsx

@@ -560,7 +560,8 @@ export function ModelsSettings({
           {tx("settings.models.presets", "Model presets")}
         </SettingsSectionTitle>
         <SettingsGroup>
-          {!settings.model_call_order_editable ? (
+          {!settings.model_call_order_editable &&
+          settings.model_configuration_migratable !== false ? (
             <div className="flex flex-col gap-4 px-4 py-4 sm:flex-row sm:items-center sm:justify-between sm:px-5">
               <div className="flex min-w-0 items-start gap-3">
                 <span className="grid h-9 w-9 shrink-0 place-items-center rounded-control bg-muted text-muted-foreground">

webui/src/lib/types.ts

@@ -595,6 +595,8 @@ export interface SettingsPayload {
   }>;
   model_call_order: string[];
   model_call_order_editable: boolean;
+  /** Whether an actual legacy model configuration is available to convert. */
+  model_configuration_migratable?: boolean;
   created_model_preset?: string;
   created_provider?: string;
   providers: Array<{

webui/src/tests/settings-models.test.tsx

@@ -690,6 +690,7 @@ describe("Settings models", () => {
       model_presets: [defaultPreset],
       model_call_order: [],
       model_call_order_editable: false,
+      model_configuration_migratable: true,
     };
     const fetchMock = vi.fn(async (input: RequestInfo | URL) => {
       const url = String(input);
@@ -725,6 +726,48 @@ describe("Settings models", () => {
     expect(screen.queryByText("Default")).not.toBeInTheDocument();
   });
 
+  it("starts fresh users with an empty preset list instead of legacy conversion", async () => {
+    const base = settingsPayload();
+    const freshPayload: SettingsPayload = {
+      ...base,
+      agent: {
+        ...base.agent,
+        model: "anthropic/claude-opus-4-5",
+        provider: "auto",
+        resolved_provider: null,
+        has_api_key: false,
+        model_preset: "default",
+      },
+      model_presets: [
+        {
+          ...base.model_presets[0],
+          name: "default",
+          label: "Default",
+          active: true,
+          is_default: true,
+          model: "anthropic/claude-opus-4-5",
+          provider: "auto",
+          resolved_provider: null,
+        },
+      ],
+      model_call_order: [],
+      model_call_order_editable: false,
+      model_configuration_migratable: false,
+      providers: [],
+    };
+    vi.stubGlobal("fetch", vi.fn(() => new Promise<Response>(() => {})));
+
+    renderSettingsView({ initialSection: "models", initialSettings: freshPayload });
+
+    expect(
+      await screen.findByRole("button", { name: "New model preset" }),
+    ).toBeInTheDocument();
+    expect(
+      screen.queryByRole("button", { name: "Convert to presets" }),
+    ).not.toBeInTheDocument();
+    expect(screen.queryByText("claude-opus-4-5")).not.toBeInTheDocument();
+  });
+
   it("does not expose the synthetic default configuration as a WebUI preset", async () => {
     const base = settingsPayload();
     const payload: SettingsPayload = {