feat: add advanced context actions and optional translation

AGENTS.md

@@ -46,10 +46,17 @@ After `npm test`, use `npm run dev` and confirm:
 
 - `gpt <query>` opens ChatGPT, the provider stays non-default, and Firefox
   search settings can configure it.
-- The Options/Preferences tab renders all five settings plus Restore defaults,
+- The Options/Preferences tab renders the settings plus Restore defaults,
   in both light and dark themes and at a narrow window width, and values
   persist across a restart.
-- The right-click **Ask ChatGPT** item appears only when text is selected.
+- **Context menu → Simple** shows the direct **Ask ChatGPT** item only for
+  selected text. **Advanced** shows the contextual submenu; selection takes
+  precedence over links. **Off** hides the menu. Switch modes without restarting
+  and confirm Alt+Shift+G still works in every mode. Restore defaults returns
+  to Simple with Translate hidden, and preferences persist across a restart.
+- Enable Translate and check Ask each time, preferred language, Enter, Escape,
+  and Cancel. Confirm long selections require consent before shortening and
+  link URLs are never shortened. Check concurrent dialogs retain separate data.
 - `Alt+Shift+G` acts on the selection and opens a blank chat when nothing is
   selected or on a restricted page such as `about:config`. Press the key to test
   this — `commands.getAll()` reports a shortcut as registered even when Firefox