TherapyGym: Evaluating and Aligning Clinical Fidelity and Safety in Therapy Chatbots. - Fangrui Huang; Souhad Chbeir; Arpandeep Khatua; Sheng Wang; Sijun Tan; Kenan Ye; Lily Bailey; Merryn Daniel; Ryan Louie; Sanmi Koyejo; Ehsan Adeli 001 (CoRR, 2026)