Lithuania’s National Digital Health System Architecture, Evolution, and Lessons From a Centralized Approach Using Longitudinal Document Analysis: Descriptive National Case Study - Austėja Dapkutė; Olegas Niakšu; Julius Juodakis; Danguolė Jankauskienė; Justas Trinkūnas; Arvydas Laurinavičius; Tomas Jovaiša; Donata Ringaitienė; Martyna Atraškevičienė; Rytis Masiliūnas (JMIR Formative Research, 2026)