v0.03: fix hamburger menu clipping off right edge of screen

Change menu anchor from bottomLeft() to bottomRight() so Qt's built-in
overflow logic flips the menu leftward when the button is near the right
screen edge. All bookmarks now visible.

browser.py

@@ -418,9 +418,10 @@ class KioskOverlay(QWidget):
         mgr_act = QAction("  ⚙  Manage Bookmarks…", menu)
         mgr_act.triggered.connect(self.open_manager)
         menu.addAction(mgr_act)
-        # Show menu below the hamburger button
+        # Show menu below the hamburger button, anchored to right edge so
+        # Qt's overflow logic flips it leftward (avoids clipping off-screen).
         menu.exec_(self.burger_btn.mapToGlobal(
-            self.burger_btn.rect().bottomLeft()))
+            self.burger_btn.rect().bottomRight()))
 
     def _build_menu(self, items):
         menu = QMenu()