GRB 221009A: Observations with LST-1 of CTAO and Implications for Structured Jets in Long Gamma-Ray Bursts - Abe,K.; Abe,S.; Abhishek,A.; Acero,F.; Aguasca-Cabot,A.; Agudo,I.; Alispach,C.; Ambrosino,D.; Ambrosino,F.; Antonelli,L.A.; Aramo,C.; Arbet-Engels,A.; et al. (Astrophysical Journal Letters, 2025)