Bug(firefox): `chrome.action is undefined`

[Alexandre-Bigot]

Firefox 140.5.0esr

[Browserlet BG] handleContextMatch error: TypeError: can't access property "setBadgeText", chrome.action is undefined

[mmaudet]

Thanks @Alexandre-Bigot

Root cause

Firefox uses Manifest V2 where the badge/action API is exposed as browser.browserAction, not browser.action (which is MV3-only). Our existing Firefox polyfill (utils/firefoxPolyfill.ts) correctly aliases chrome to browser, but browser.action doesn't exist in MV2 — hence the chrome.action is undefined error.

Fix

Extended the Firefox polyfill to alias browser.action to browser.browserAction when running under MV2. This makes all 5 chrome.action.* call sites (badge text, badge color, onClicked) work transparently on Firefox without any changes to the consuming code.

How to verify. (I did a simple test on my side)

1. Load the extension in Firefox (about:debugging > Load Temporary Add-on)
2. Navigate to a page that matches a trigger context (e.g. a page with a configured URL pattern)
3. Verify:
   - The badge count appears on the extension icon when scripts are suggested
   - Clicking the extension icon opens the sidebar
   - Dismissing suggestions clears the badge
   - No chrome.action is undefined error in the Browser Console (Ctrl+Shift+J)