feat: Return a copy of workspaces when trying to fetch it to prevent mutations, b=no-bug, c=tabs, workspaces

src/browser/themes/shared/tabbrowser/tabs-css.patch

@@ -1,5 +1,5 @@
 diff --git a/browser/themes/shared/tabbrowser/tabs.css b/browser/themes/shared/tabbrowser/tabs.css
-index 8a4d3860b344e2dc2128cfc2b1673de582e19c7c..fef63d687ba4e816d3d36f34d4a39adef06359c9 100644
+index 8a4d3860b344e2dc2128cfc2b1673de582e19c7c..086171783cd9a8629ccf4b2e90813e58c4793878 100644
 --- a/browser/themes/shared/tabbrowser/tabs.css
 +++ b/browser/themes/shared/tabbrowser/tabs.css
 @@ -21,7 +21,7 @@
@@ -111,7 +111,7 @@ index 8a4d3860b344e2dc2128cfc2b1673de582e19c7c..fef63d687ba4e816d3d36f34d4a39ade
  }
  
 -#tabbrowser-arrowscrollbox[orient="vertical"] > #tabbrowser-arrowscrollbox-periphery > #tabs-newtab-button,
-+#tabbrowser-arrowscrollbox[orient="vertical"] #tabbrowser-arrowscrollbox-periphery > #tabs-newtab-button,
++#tabs-newtab-button,
  #vertical-tabs-newtab-button {
    appearance: none;
    min-height: var(--tab-min-height);

src/zen/sessionstore/ZenWindowSync.sys.mjs

@@ -312,7 +312,10 @@ class nsZenWindowSync {
     if (flags & SYNC_FLAG_ICON) {
       aTargetItem.removeAttribute('zen-has-static-icon');
       if (gBrowser.isTab(aOriginalItem)) {
-        gBrowser.setIcon(aTargetItem, gBrowser.getIcon(aOriginalItem));
+        gBrowser.setIcon(
+          aTargetItem,
+          aOriginalItem.getAttribute('image') || gBrowser.getIcon(aOriginalItem)
+        );
       } else if (aOriginalItem.isZenFolder) {
         // Icons are a zen-only feature for tab groups.
         gZenFolders.setFolderUserIcon(aTargetItem, aOriginalItem.iconURL);

src/zen/tabs/ZenPinnedTabManager.mjs

@@ -32,6 +32,7 @@ class ZenPinnedTabsObserver {
     );
     ChromeUtils.defineESModuleGetters(lazy, {
       E10SUtils: 'resource://gre/modules/E10SUtils.sys.mjs',
+      TabStateCache: 'resource:///modules/sessionstore/TabStateCache.sys.mjs',
     });
     this.#listenPinnedTabEvents();
   }
@@ -486,6 +487,9 @@ class nsZenPinnedTabManager extends nsZenDOMOperatedFeature {
           if (icon) {
             tab.setAttribute('zen-has-static-icon', 'true');
           }
+          lazy.TabStateCache.update(tab.permanentKey, {
+            image: null,
+          });
         })
         .catch((err) => {
           console.error(err);

src/zen/workspaces/ZenWorkspaces.mjs

@@ -824,7 +824,7 @@ class nsZenWorkspaces {
       this.#activeWorkspace = this._tempWorkspace?.uuid;
       return this._workspaceCache;
     }
-    return this._workspaceCache;
+    return [...this._workspaceCache];
   }
 
   async workspaceBookmarks() {
@@ -1210,7 +1210,7 @@ class nsZenWorkspaces {
     }
     if (!this.#contextMenuData.workspaceId) {
       separator.hidden = false;
-      for (const workspace of [...this._workspaceCache].reverse()) {
+      for (const workspace of this.getWorkspaces().reverse()) {
         const item = this.generateMenuItemForWorkspace(workspace);
         item.addEventListener('command', (e) => {
           this.changeWorkspaceWithID(e.target.closest('menuitem').getAttribute('zen-workspace-id'));
@@ -1363,7 +1363,7 @@ class nsZenWorkspaces {
     if (this.privateWindowOrDisabled) {
       return;
     }
-    const workspaces = this.getWorkspaces();
+    const workspaces = this._workspaceCache;
     const workspace = workspaces.find((w) => w.uuid === id);
     if (!workspace) {
       console.warn(`Workspace with ID ${id} not found for reordering.`);
@@ -1382,8 +1382,10 @@ class nsZenWorkspaces {
       return;
     }
     workspaces.splice(newPosition, 0, workspace);
-    // Propagate the changes
-    this.#propagateWorkspaceData();
+    // Propagate the changes if the order has changed
+    if (currentIndex !== newPosition) {
+      this.#propagateWorkspaceData();
+    }
   }
 
   async openWorkspaceCreation() {

src/zen/workspaces/zen-workspaces.css

@@ -99,6 +99,8 @@
     & toolbarbutton {
       margin: 0;
       background: transparent;
+      /* Ignore press state when in overflow, to allow clicks to happen */
+      scale: 1 !important;
     }
 
     /* Inlcude separately since ther'es a bug in the