Design and Empirical Evaluation of a Four-Layer AI Agent Architecture for Automated Web Application Security Testing. - Kulambayev, Bakhytzhan; Astaubayeva, Gulnar; Mukanova, Zhanna; Makhmetova, Kuralay; Mambetov, Saken; Joldasbayev, Serik (Engineering, Technology & Applied Science Research, 2026)