pysrat 0.2.6

• refactor binomial regression wrappers (glm_binomial, glmnet_binomial) and align C++/pybind integration
• add Python-side validation for binomial response (y/n_trials) in binomial GLM/GLMNET wrappers
• simplify NHPPData constructors to use from_intervals as the base path and remove from_event_times