Summary:
Modernized context-search UX — v4.0: action-first menu, 10 engines, improved icons and layout.
What's new: Reworked menu structure so the top menu shows three actions (New Tab / New Window / New Private Window) and each action lists the 10 search engines; replaced Baidu with Kagi; added a modern SVG icon for the add-on; migrated to Manifest V3 service worker background; improved labels and accessibility of context menu entries.
Version: 4.0
Compatibility: Firefox 140.0 and later
Permissions: contextMenus, tabs (required to create menus and open search results); privacy remains optional (not used by default).
Privacy: No user data is collected or transmitted by the extension. Selected text is encoded and only used to build search URLs sent directly to the chosen search engine.

Release Notes (detailed)
UI and structure
Top-level menu now presents the three primary actions: New Tab, New Window, New Private Window. Each action expands to list the supported search engines.
Menu entries use concise emoji-based labels for visual clarity in context menus.
New toolbar/extension icon added at icon.svg to modernize listing and toolbar display.
Engines
Engines supported (10): Google, Bing, DuckDuckGo, Brave, Ecosia, Startpage, Yahoo, Yandex, Perplexity, Kagi.
Baidu removed and replaced by Kagi (more consistent results and broader availability).
Implementation
Background code migrated to MV3 service worker style (background.service_worker in manifest.json) and modularized menu creation logic in background.js.
Improved robustness on startup/install (onInstalled and onStartup handlers) and safer URL encoding (trim + slice + encodeURIComponent).
Fixes & improvements
Cleaner error logging for menu and window/tab creation failures.
Reduced menu depth for quicker selection of common actions.
Files changed
manifest.json — updated to version 4.0, added action/icons, switched to service worker.
background.js — refactored menu structure, replaced engine list.
icon.svg — new extension icon.

Added a sub-menu with three options:
Search for "your text"
├── 🔍 New Tab
├── 🪟 New Window
└── 🕵️ New Private Window

Added search engine options:
1. Google
2. Bing
3. DuckDuckGo
4. Yahoo
5. Brave Search
6. Ecosia
7. Startpage
8. Yandex
9. Baidu
10. Perplexity

The context menu entry will present the search engine selection sub-menu, which will further extend to three more options mentioned above.