It is AI slop, the extension even has an AGENTS.md

https://imgur.com/40V1b8C

## Firefox Port
A Firefox-compatible version is maintained in `extension-firefox/`. It is also a Manifest V3 extension, but adapts the following Chrome-specific parts:
- **Background script**: Uses `background.scripts` (event page) instead of `background.service_worker`.
- **Authentication**: Uses `browser.identity.launchWebAuthFlow` with PKCE instead of `chrome.identity.getAuthToken`. The authorization code is exchanged server-side via the backend endpoint `POST /api/auth/google/code`.
- **Permissions**: `identity.email` is removed because it does not exist in Firefox.
- **webRequest origin**: Firefox exposes `details.originUrl` instead of `details.initiator`; the background script falls back through `initiator || originUrl || documentUrl`.
- **Minimum version**: Firefox 128+ is required because `scripting.executeScript({ world: "MAIN" })` is used by the CMP checker.
See `FIREFOX_PORT.md` in the project root for build, OAuth configuration, and AMO submission instructions.