Changes in version 1.0.0 (2026-06-01)                  

Initial release

  - csem_gt() implements the three relative-error estimators of Brennan
    (1998) -- full, large_a, uncorrelated -- together with the
    closed-form absolute error variance (Brennan 1998, eq. 20).
  - Closed-form analytical sampling variances and item-resampling
    bootstrap variances for all four estimators.
  - Quadratic smoothing of conditional error variances on observed
    score, with optional exclusion of floor and ceiling cases.
  - D-study extrapolation via n_items_D.
  - S3 class csem with full method set: print, summary, plot,
    as.data.frame, by_score, coef.
  - iowa_like synthetic dataset calibrated to the ITED Vocabulary Test.
  - Two vignettes: tutorial introduction and worked examples.