Show pull requests as Queued when they enter GitHub's merge queue

Problem

When a linked pull request is approved and then added to GitHub's merge queue, T3 Code continues to display its status as Approved. GitHub displays the pull request as Queued, so T3 Code's status is stale and makes it look as though the merge action has not taken effect.

Expected behavior

T3 Code should recognize GitHub's merge-queue state and display a yellow Queued status for the linked pull request. Once GitHub merges the pull request, T3 Code should transition it to Merged as usual.

Steps to reproduce

1. Link a pull request to a T3 Code thread.
2. Obtain the required approval and passing checks.
3. Add the pull request to GitHub's merge queue.
4. Observe that GitHub reports Queued while T3 Code still reports Approved.

Why this matters

The current status does not distinguish an approved pull request awaiting action from one already accepted into the merge queue.

Start by locating the TypeScript code that maps GitHub pull request states to T3 Code statuses, then reproduce the approved pull request entering GitHub's merge queue. Done means queued pull requests display a yellow Queued status and transition to Merged after GitHub merges them.