Problem

When a user comments @qwen-code /review, the review workflow can be accepted by GitHub Actions but remain queued on the self-hosted ecs-qwen runner. In that state the PR conversation has no immediate feedback, so it looks like Qwen Code did not trigger.

This happened on #4840: the issue_comment run was created, then a later ready_for_review run replaced it through workflow concurrency, and the active review job stayed queued waiting for the self-hosted runner.

Proposal

Add a lightweight acknowledgement step that does not depend on the self-hosted review runner. When a valid review trigger is received, the workflow should quickly indicate that Qwen Code accepted the request and is queued/running, ideally with a link to the Actions run.

A minimal implementation could add a GitHub-hosted ack job that:

• runs after the same trigger eligibility checks used by the review job;
• posts a short PR comment such as Qwen Code review queued: <run link> or adds a clear reaction/status marker;
• leaves the actual review execution on the existing self-hosted ecs-qwen runner.

Expected outcome

Users can tell the review request was accepted even when the self-hosted runner is busy, without changing the review execution environment.