## Problem
Every `tests/test.sh` locates the repository with `find_repo`, which only accepts a `.git` whose `HEAD` **equals** the base commit, and otherwise writes reward 0 without running a test ("fail closed").
An agent that fixes the bug and then runs `git commit` therefore scores 0 regardless of whether the fix is right: `HEAD` has moved to its own commit, whose parent is the base commit. In one RL run (Qwen3.5-9B, terminus agent), 5 of 344 Rebench rollouts were zeroed this way without being graded (e.g. `cs-si__eodag-634`: edit `eodag/utils/__init__.py`, self-test, `git add`, `git commit`, submit -> `no repository at base commit`). For RL this rewards "never touch git", not "fix the bug".
(Rollouts that `git checkout` an unrelated or older commit and fix the bug there, e.g. 9 rollouts on `maas__python-libmaas-227`, are also zeroed. That is correct and stays unchanged: the graded code is not the task's code.)
## Change
Only the repo lookup and the test-surface reset change; th…
