Get Student Evaluation

Returned for the student v2-evaluation GET. latest_evaluation is optional — the rubric still travels back even when the student hasn't submitted yet, so frontend surfaces can compute assignment-level totals over the full set of rubric'd exercises.

Multimodal attempts additionally expose the submitted photos (bounding boxes inside the evaluation reference them by index), the grading status, and — V3 variant — the LLM transcription of the copy.