Deletes all LinUCB and ε-greedy code from ml/serving: score, reward, stats, reset, features endpoints; feature vector builders; per-user state file helpers; related Pydantic models; numpy/math/time imports. Removes test_score.py (pure bandit unit tests). 40 remaining tests pass. STATE_DIR kept — nats_consumer still writes sync metadata there. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>