diff --git a/AGENTS.md b/AGENTS.md
index 24ded422..186cc4f7 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -451,7 +451,7 @@ A single store with N properties means every subscriber re-evaluates on every st
 
 ## Validation expectations
 
-- Run `bun run type-check` and `bun run lint` before finalizing source-code changes that can affect TypeScript, runtime behavior, builds, lint rules, package resolution, or generated assets. For docs-only or isolated config-only changes, run the narrowest relevant validation instead (for example JSON/schema validation) and do not run the full checks unless the change can affect code execution.
+- Run `bun run type-check` and `bun run lint` before finalizing source-code changes that can affect TypeScript, runtime behavior, builds, lint rules, package resolution, or generated assets. Use a sufficiently long tool timeout for these workspace-wide checks (for example 240000ms) so successful package-level results are not lost to a tool timeout. For docs-only or isolated config-only changes, run the narrowest relevant validation instead (for example JSON/schema validation) and do not run the full checks unless the change can affect code execution.
 - For hot-path changes, verify behavior under streaming or repeated events, not just static render.
 - For sync or startup changes, verify fresh load, retry/failure, and restart behavior.
 - For session changes, verify create, stream, abort, permission, archive/delete, and revisit flows when relevant.
diff --git a/packages/ui/src/components/layout/Header.tsx b/packages/ui/src/components/layout/Header.tsx
index 1ae2aa9d..9a76dff8 100644
--- a/packages/ui/src/components/layout/Header.tsx
+++ b/packages/ui/src/components/layout/Header.tsx
@@ -1417,16 +1417,6 @@ export const Header: React.FC<HeaderProps> = ({
     toggleSidebar();
   }, [blurActiveElement, isMobile, isSessionSwitcherOpen, setSessionSwitcherOpen, toggleSidebar]);
 
-  const handleOpenWindowsAppMenu = React.useCallback((event: React.MouseEvent<HTMLButtonElement>) => {
-    const rect = event.currentTarget.getBoundingClientRect();
-    void invokeDesktop('desktop_show_app_menu', {
-      x: rect.left,
-      y: rect.bottom,
-    }).catch((error) => {
-      console.warn('[header] failed to open app menu', error);
-    });
-  }, []);
-
   const handleOpenDraftMiniChat = React.useCallback(() => {
     void invokeDesktop('desktop_open_draft_mini_chat_window', {
       directory: normalize(openDirectory || activeProject?.path || ''),
@@ -2154,15 +2144,6 @@ export const Header: React.FC<HeaderProps> = ({
         className="app-region-no-drag shrink-0 self-stretch transition-[width] duration-200 ease-[cubic-bezier(0.22,1,0.36,1)] motion-reduce:transition-none"
         style={{ width: headerControlsSpacerWidth }}
       />
-      {isWindowsElectronDesktop ? (
-        <HeaderIconActionButton
-          title={t('header.actions.openAppMenu')}
-          ariaLabel={t('header.actions.openAppMenuAria')}
-          onClick={handleOpenWindowsAppMenu}
-          className={`${desktopHeaderIconButtonClass} shrink-0`}
-          Icon={'menu-2'}
-        />
-      ) : null}
       {/* Sidebar toggle + project actions live in the persistent
           TitlebarLeftControls overlay; the header reserves matching left space
           via padding (see headerStyle) when the sidebar is collapsed. */}
diff --git a/packages/ui/src/components/layout/TitlebarLeftControls.tsx b/packages/ui/src/components/layout/TitlebarLeftControls.tsx
index 33636d56..9f29795d 100644
--- a/packages/ui/src/components/layout/TitlebarLeftControls.tsx
+++ b/packages/ui/src/components/layout/TitlebarLeftControls.tsx
@@ -7,6 +7,7 @@ import { useI18n } from '@/lib/i18n';
 import { useProjectActionsContext } from '@/hooks/useProjectActionsContext';
 import { ProjectActionsButton } from '@/components/layout/ProjectActionsButton';
 import { formatShortcutForDisplay, getEffectiveShortcutCombo } from '@/lib/shortcuts';
+import { invokeDesktop } from '@/lib/desktop';
 
 const ICON_BUTTON_CLASS =
   'app-region-no-drag inline-flex h-8 w-8 items-center justify-center gap-2 rounded-md typography-ui-label font-medium text-foreground focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-primary hover:bg-interactive-hover transition-colors';
@@ -31,6 +32,22 @@ export const TitlebarLeftControls: React.FC = () => {
   const clusterRef = React.useRef<HTMLDivElement | null>(null);
 
   const toggleShortcut = formatShortcutForDisplay(getEffectiveShortcutCombo('toggle_sidebar', shortcutOverrides));
+  const isWindowsElectronDesktop = React.useMemo(() => {
+    if (typeof window === 'undefined') {
+      return false;
+    }
+    return Boolean(window.__OPENCHAMBER_ELECTRON__) && window.__OPENCHAMBER_PLATFORM__ === 'win32';
+  }, []);
+
+  const handleOpenWindowsAppMenu = React.useCallback((event: React.MouseEvent<HTMLButtonElement>) => {
+    const rect = event.currentTarget.getBoundingClientRect();
+    void invokeDesktop('desktop_show_app_menu', {
+      x: rect.left,
+      y: rect.bottom,
+    }).catch((error) => {
+      console.warn('[titlebar] failed to open app menu', error);
+    });
+  }, []);
 
   React.useEffect(() => {
     if (typeof document === 'undefined') {
@@ -71,6 +88,24 @@ export const TitlebarLeftControls: React.FC = () => {
       }}
     >
       <div ref={clusterRef} className="flex items-center gap-2">
+        {isWindowsElectronDesktop ? (
+          <Tooltip>
+            <TooltipTrigger asChild>
+              <button
+                type="button"
+                onClick={handleOpenWindowsAppMenu}
+                aria-label={t('header.actions.openAppMenuAria')}
+                className={cn(ICON_BUTTON_CLASS, 'shrink-0')}
+              >
+                <Icon name="menu-2" className="h-[18px] w-[18px]" />
+              </button>
+            </TooltipTrigger>
+            <TooltipContent>
+              <p>{t('header.actions.openAppMenu')}</p>
+            </TooltipContent>
+          </Tooltip>
+        ) : null}
+
         <Tooltip>
           <TooltipTrigger asChild>
             <button