SINT 0.1.0

• Friedkin-Johnsen core: fj_check() validates inputs and reports convergence diagnostics, fj_equilibrium() and fj_influence() compute the fixed point and the total influence matrix, fj_simulate() iterates the dynamics. Signed influence matrices are supported.
• sint_simulate() simulates latent and manifest dynamics with influence matrices and susceptibilities that may depend on time and state.
• Response functions response_logistic() and response_threshold(), with climate_balance() for endogenous normative pressure.
• aggregate_quota() maps manifest responses to collective outcomes.
• row_normalize() builds influence matrices from unnormalized weights.
• influence_matrix() converts matrices, ‘igraph’ graphs and ‘network’ objects into influence matrices.
• User guide vignette, vignette("SINT").