主题与字号从页面顶栏搬进设置页的「外观」，顶部导航加上预设入口。

顶栏那套汉堡菜单在每页都要单独挂载、样式也重复，收进设置页后只剩一处改；顺手把「整组都没有曾用型号」的配置组整组收起，不再留空卡片。

tests/api-profile-usage.test.ts

@@ -45,3 +45,13 @@ describe("forgetApiProfileUsage", () => {
     expect(forgetApiProfileUsage("missing")).toBe(false);
   });
 });
+
+describe("groups with no used model", () => {
+  it("shows nothing, so the settings page hides the whole group", () => {
+    recordApiProfileUsage("used");
+    const members = [{ id: "unused-a" }, { id: "unused-b" }];
+    expect(filterUsedApiProfiles(members, loadApiProfileUsage(), null)).toEqual(
+      [],
+    );
+  });
+});