Switch to Devseis AI Act Classifier v6; 'uncertain' label for split predictions

Rename model to Devseis AI Act Classifier v5; link Hub model and dataset repos

Model card: correct licence to CC BY-SA 4.0 and add LEGAL-BERT attribution

Redesign page (Check / Results / Story / Learn), publish v5 data and evaluation, update cards

Part 1: switch to v5 model (legal-bert-small, in-Space), add GPAI rule, update stats