[BUG] Context search fails with `TypeError: can't access property "getVisibleEngines", Services.search is undefined`

[morags]

Link to the file containing the bug
https://github.com/aminomancer/uc.css.js/blob/master/JS/contextMenuMods.uc.js

Describe the bug
The context menu search sub-menu does not render. On browser startup, the browser toolbox console emits a TypeError: can't access property "getVisibleEngines", Services.search is undefined.

To Reproduce
Steps to reproduce the behavior:

1. Mark a bit of text on some webpage
2. Right-click anywhere on the page, then hover over "search with..."
3. The search engine submenu fails to render

Expected behavior
The search engine submenu renders properly, and you are able to choose an engine for executing the search query.

Screenshots
If applicable, add screenshots to help explain your problem.

Desktop (please complete the following information):

• OS: Windows 11 Pro
• Firefox update channel: Release
• Version: 150
• Build ID: 20260415192539

Additional context
Add any other context about the problem here.