SISN: Signer-Invariant Skeletal Normalization for Sign Language Production. - Ragesh M; B. Arjun K. C; Niyantarana T; T. Inish; M. Aiswarya Lakshmi; Nagarathna Ravi; E. Rajalakshmi; Bandana Raj Nandini Tikmani; Ashapurna Marndi (NCC, 2026)