New function keywords

• Added missing block keywords: epilogue and perfect_foresight_controlled_paths for proper block recognition.
• Introduced a new function-keywords category. Built-ins are highlighted as support.function.builtin.dynare:
  • Mathematical: exp, log, ln, log10, sin, cos, tan, asin, acos, atan, sinh, cosh, tanh, asinh, acosh, atanh, sqrt, cbrt, max, min, abs, sign
  • Statistical: normcdf, normpdf, erf, erfc
  • Dynare special: steady_state, expectation, var_expectation, pac_expectation
  • Note: Greek*letter functions keep the existing keyword.function.dynare class.
• Large update to statement-level keywords (hundreds added from the lexer):
  • Core additions: prior_function, posterior_function, epilogue, perfect_foresight_controlled_paths
  • Extensive option keywords, including solver, simulation, likelihood, smoother, MCMC (mh_*), particle filters, identification, method-of-moments, BVAR, homotopy, occbin, and linear solver options.
  • Block-specific additions: values, scales, cutoff, static_mfs, heterogeneity, surprise, bind/relax/error_bind/error_relax, restriction/component/target/auxname, weights/exogenize/endogenize, etc.
  • Data/file and output options: file, dirname, datafile, filename, xls_sheet, xls_range, series, output_file_tag, file_tag, simulation_file_tag.
  • Distribution keywords: gamma_pdf, beta_pdf, normal_pdf, inv_gamma_pdf, inv_gamma1_pdf, inv_gamma2_pdf, uniform_pdf, weibull_pdf.
  • Time and frequency keywords: monthly, quarterly, qoq, yoy, aoa, freq, initial_year/subperiod, final_year/subperiod.
  • Advanced and feature flags: use_dll, block, bytecode, all_values_required, no_static, differentiate_forward_vars, parallel_local_files,