chore: Update alpha-build.sh script to handle xvfb-run not found and enable LTO only when not cross-compiling

- Add conditional check for xvfb-run command availability
- Enable LTO (Link Time Optimization) only when not cross-compiling

Related recent commits:
- Update Zen Browser styles for dark mode compatibility
- Update Windows mozconfig and ZenWorkspaces.mjs

.github/workflows/src/alpha-build.sh

@@ -1,12 +1,20 @@
 
 export ZEN_RELEASE=1
-# Check if xfvb is installed
-if ! command -v xvfb-run &> /dev/null
+
+if command -v apt-get &> /dev/null
 then
-  echo "xvfb-run could not be found, running without it"
+  sudo apt-get update
+  sudo apt-get install -y xvfb
+fi
+
+# Check if xfvb is installed
+if ! command -v Xvfb &> /dev/null
+then
+  echo "Xvfb could not be found, running without it"
   pnpm build
 else
+  Xvfb :2 -screen 0 1024x768x24 &
   export LLVM_PROFDATA=$HOME/.mozbuild/clang/bin/llvm-profdata
   export DISPLAY=:2
-  xvfb-run -s "-screen 0 1920x1080x24 -nolisten local" pnpm build
 fi
+pnpm build

src/browser/base/content/zenThemeModifier.js

@@ -135,6 +135,9 @@ var ZenThemeModifier = {
     this._updateZenAvatar();
     window.matchMedia('(prefers-color-scheme: dark)').addEventListener('change', this._onPrefersColorSchemeChange.bind(this));
 
+    this._updateTabsToolbar();
+    window.addEventListener("resize", this._onResize.bind(this));
+
     this.closeWatermark();
   },
 
@@ -142,6 +145,19 @@ var ZenThemeModifier = {
     this._updateZenAvatar();
   },
 
+  _onResize(event) {
+    this._updateTabsToolbar();
+  },
+
+  _updateTabsToolbar() {
+    // Set tabs max-height to the "toolbar-items" height
+    const toolbarItems = document.querySelector("#TabsToolbar > .toolbar-items");
+    const tabs = document.getElementById("tabbrowser-arrowscrollbox");
+    const toolbarRect = toolbarItems.getBoundingClientRect();
+    tabs.style.maxHeight = toolbarRect.height - toolbarRect.top + "px";
+    console.log("ZenThemeModifier: set tabs max-height to", toolbarRect.height + "px");
+  },
+
   _updateZenAvatar() {
     const mainWindowEl = document.documentElement;
     // Dont override the sync avatar if it's already set

src/browser/themes/shared/zen-browser-shared.css

@@ -397,6 +397,10 @@ toolbarbutton#scrollbutton-up {
   display: none;
 }
 
+#TabsToolbar-customization-target {
+  height: 100%;
+}
+
 #tabbrowser-tabs {
   margin-inline-start: 0 !important;
   padding-inline-start: 0 !important;
@@ -404,6 +408,7 @@ toolbarbutton#scrollbutton-up {
   /*background: light-dark(rgba(0,0,0,.05), rgba(255,255,255,.05));*/
   margin: 0 !important;
   border: none;
+  height: 100%;
 }
 
 #tabbrowser-arrowscrollbox {