experiment: log 15 experiments, final score 0.8861
Best config found: DOC_FREQ_CUTOFF=0.5, MIN_SHARED_TAGS=1, MAX_DEGREE=12,
CONTEXT_NO_MODAL_WEIGHT=1. Score improved 0.8785→0.8861. D-rate 66%→61%.
Orphan rate 46%→6%. Parametric ceiling reached — D-rate needs code fix.