gh-16314: Hide Set Profile option in private windows

src/zen/common/modules/ZenVerticalTabsManager.mjs

@@ -88,6 +88,7 @@ window.gZenVerticalTabsManager = {
       <menuseparator/>
     `);
     const menu = fragment.firstElementChild;
+    const separator = menu.nextElementSibling;
     menu.addEventListener("popupshowing", event =>
       gZenWorkspaces.updateWorkspaceActionsMenuContainer(event)
     );
@@ -98,7 +99,9 @@ window.gZenVerticalTabsManager = {
     const contextMenu = document.getElementById("toolbar-context-menu");
     contextMenu.addEventListener("popupshowing", event => {
       if (event.target === contextMenu) {
-        menu.hidden = !gZenWorkspaces.shouldShowContainers;
+        const hidden = !gZenWorkspaces.shouldShowContainers;
+        menu.hidden = hidden;
+        separator.hidden = hidden;
       }
     });
     document

src/zen/spaces/ZenSpaceManager.mjs

@@ -1523,6 +1523,7 @@ class nsZenWorkspaces {
 
   get shouldShowContainers() {
     return (
+      !this.isPrivateWindow &&
       Services.prefs.getBoolPref("privacy.userContext.ui.enabled") &&
       !!ContextualIdentityService.getPublicIdentities().length
     );

src/zen/tests/spaces/browser_private_mode.js

@@ -22,6 +22,24 @@ add_task(async function test_Private_Mode() {
     "Private window should start with a zen empty tab"
   );
 
+  Assert.ok(
+    !privateWindow.gZenWorkspaces.shouldShowContainers,
+    "Containers/profiles should not be shown in private windows"
+  );
+
+  const popup = privateWindow.document.getElementById("zenWorkspaceMoreActions");
+  privateWindow.gZenWorkspaces.updateWorkspaceActionsMenu({
+    target: popup,
+  });
+
+  const openInContainerMenuItem = privateWindow.document.getElementById(
+    "context_zenWorkspacesOpenInContainerTab"
+  );
+  Assert.ok(
+    openInContainerMenuItem.hidden,
+    "Set Profile menu should be hidden in private window"
+  );
+
   await BrowserTestUtils.closeWindow(privateWindow);
   await SpecialPowers.popPrefEnv();
 });