fix: use path-based menuId to prevent collisions in nested submenus

[chrism]

Summary

• prepareMenu passes menuIndex as index when recursing into submenus, losing the original bar button item index
• This causes menuId collisions between actions in different submenus and sibling toolbar menus at the same position
• Fix threads a path string through recursion to track nesting depth, while preserving the original bar button item index

Problem

Given two toolbar menu buttons — a filter menu at bar button index 1 containing submenus, and a sort menu at bar button index 2:

Toolbar:
  [+] button (index 0)
  [filter] menu (index 1)     ← contains Location, Item Type, Quality submenus
  [sort] menu (index 2)       ← contains Title, Gear Type, Date Added actions

When prepareMenu recurses into the Quality submenu (at menuIndex 2 inside the filter menu), it calls:

prepareMenu(menuItem, menuIndex, side)  // menuIndex=2, replacing index=1

The first action inside Quality then gets menuId: "0-2-right", which collides with the first action in the sort menu ("0-2-right"). Selecting a quality filter fires the sort handler instead.

Fix

Add a path parameter that tracks position through nesting, while keeping the original bar button index:

const prepareMenu = (
  menu, index, side,
  path = '',  // NEW
) => {
  return {
    ...menu,
    items: menu.items.map((menuItem, menuIndex) => {
      const currentPath = path ? `${path}.${menuIndex}` : `${menuIndex}`;
      // ...
      if (menuItem.type === 'submenu') {
        return {
          ...menuItem,
          ...prepareMenu(menuItem, index, side, currentPath),
          //                       ^^^^^ preserved (was menuIndex)
        };
      }
      return {
        ...menuItem,
        menuId: `${currentPath}-${index}-${side}`,
        //        ^^^^^^^^^^^^ path-based (was menuIndex)
      };
    }),
  };
};

Before: Quality "All" = 0-2-right (collides with Sort "Title" = 0-2-right)
After: Quality "All" = 2.0-1-right, Sort "Title" = 0-2-right (unique)

Verified

• Toolbar with multiple menu buttons — actions in each menu fire the correct handler
• Nested submenus (inline sections) within a toolbar menu — no cross-talk with sibling toolbar menus
• Single menu button with no submenus — no regression (path defaults to menuIndex)