fix: correct 50 decision_dates mis-backfilled via HUDOC prefix-match collision (exact-itemid re-fetch)

fix: scrub verdict-conclusion sentences (124 own-article label leaks -> 0), fill respondent=UKRAINE for ukr group, fill 79 missing decision_dates from ECLI/HUDOC

LiveHumanRightsBench static eval set: balanced 1K regular + 1K Ukrainian (ECtHR, verdict-free, dated)