[BUG] Model reports a fix as done without running the failing tests, and the fix was incomplete

Given a pasted CI failure (3 tests), the model identified a missing handler registration, applied it, and reported the cause as fixed without running the tests. The change was incomplete: a second flag was required for the handler to receive the identifier it needs, so the same tests would still have failed. The model only discovered this later while defending a line from another change.

Expected: reproduce a pasted test failure and confirm the fix against it, or clearly say the fix is unverified and trace the handler's full call path before claiming the cause.