fix: lock button visual state now updates correctly outside edit mode

Fixed bug where the lock/unlock button's icon and title didn't update when
toggling lock state outside of edit mode. The logical state changed correctly
(widgets locked/unlocked), but the button appearance remained stale.

Root Cause:
- toggleLock() correctly updates the button element
- When in dropdown/menu mode (narrow screens), menu items are static snapshots
- Edit mode toggle refreshed the menu (via headerOverflowManager.refresh())
- Lock button toggle did NOT refresh the menu
- Result: stale button appearance in dropdown menus

Solution:
- Added headerOverflowManager.refresh() call after toggleLock()
- Follows the exact same pattern as edit mode toggle (lines 323-326)
- Uses setTimeout(50ms) to ensure DOM updates complete first

Changes:
- src/systems/dashboard/dashboardIntegration.js (lines 338-341)
  Added 4 lines to refresh menu after lock state change

Result:
Lock button now correctly updates its visual state (icon: lock/lock-open,
title: "Lock Widgets"/"Unlock Widgets") whether in edit mode or not, and
whether visible directly or in dropdown/hamburger menus.

src/systems/dashboard/dashboardIntegration.js

@@ -335,6 +335,10 @@ function setupDashboardEventListeners(dependencies) {
             if (dashboardManager && dashboardManager.editManager) {
                 console.log('[RPG Companion] Lock button clicked');
                 dashboardManager.editManager.toggleLock();
+                // Refresh header overflow menu to reflect lock button state change
+                if (headerOverflowManager) {
+                    setTimeout(() => headerOverflowManager.refresh(), 50);
+                }
             }
         });
     }