fix(accounts): stabilize extreme toggle bursts

tests/account-ui.test.ts

@@ -13,6 +13,7 @@ import {
   matchesAccountModeFilter,
   mergeAccountToggleSettings,
   pruneAccountRowSelection,
+  resolveAccountToggleIntentEnabled,
   resolveAccountUsername,
   resolveVisibleAccountKind,
   sortAccountServices
@@ -143,6 +144,12 @@ describe("account usernames", () => {
 });
 
 describe("account toggle bursts", () => {
+  it("toggles from the synchronous pending intent when the controlled DOM value lags", () => {
+    expect(resolveAccountToggleIntentEnabled(undefined, false)).toBe(false);
+    expect(resolveAccountToggleIntentEnabled(false, false)).toBe(true);
+    expect(resolveAccountToggleIntentEnabled(true, true)).toBe(false);
+  });
+
   it("serializes different account intents without dropping the second task", async () => {
     const queue = createAccountToggleQueue();
     const events: string[] = [];

tests/settings-view.test.tsx

@@ -1356,6 +1356,16 @@ describe("account workspace", () => {
 });
 
 describe("settings App integration", () => {
+  it("serializes local and online backup imports with pending account mutations", () => {
+    const localImport = sourceBlock(appSource, "const onImportBackup", "const onCreateOnlineBackup");
+    const onlineImport = sourceBlock(appSource, "const onImportOnlineBackup", "const onCopyOnlineBackupKey");
+
+    expect(localImport).toContain("runQueuedSettingsMutation");
+    expect(onlineImport).toContain("runQueuedSettingsMutation");
+    expect(localImport.indexOf("runQueuedSettingsMutation")).toBeLessThan(localImport.indexOf("runLocalBackupImport"));
+    expect(onlineImport.indexOf("runQueuedSettingsMutation")).toBeLessThan(onlineImport.indexOf("window.rd.importOnlineBackup"));
+  });
+
   it("projects provider order entries with logos and explicit login modes", () => {
     const settings = createRendererSettings({
       ...defaultSettings(),