test(app): seed e2e settings fields without assuming an empty settings blob

The e2e page fixture now stores a chat display before specs run, so seeds that
skipped whenever any settings blob existed never wrote their own field. They now
merge into the blob and skip only once their own field is stored.

packages/app/e2e/browser/changes-pane.spec.ts

@@ -1415,12 +1415,14 @@ test("collapsing and expanding restores the real horizontal scroll offset", asyn
 async function useCodeFont(page: Page, codeFontSize: number): Promise<void> {
   await page.addInitScript(
     ({ settingsKey, fontSize }) => {
-      if (localStorage.getItem(settingsKey)) {
+      const settings = JSON.parse(localStorage.getItem(settingsKey) ?? "{}");
+      if (settings.codeFontSize !== undefined) {
         return;
       }
       localStorage.setItem(
         settingsKey,
         JSON.stringify({
+          ...settings,
           theme: "dark",
           sendBehavior: "interrupt",
           serviceUrlBehavior: "ask",

packages/app/e2e/support/helpers/sidebar-nav-settings.ts

@@ -63,8 +63,9 @@ export async function seedSidebarFooterPreferences(
 ): Promise<void> {
   await page.addInitScript(
     ({ key, sidebarFooterItems }) => {
-      if (localStorage.getItem(key)) return;
-      localStorage.setItem(key, JSON.stringify({ sidebarFooterItems }));
+      const settings = JSON.parse(localStorage.getItem(key) ?? "{}");
+      if (settings.sidebarFooterItems) return;
+      localStorage.setItem(key, JSON.stringify({ ...settings, sidebarFooterItems }));
     },
     { key: APP_SETTINGS_KEY, sidebarFooterItems: preferences },
   );