OLSengine 1.1.0

New features

• Added panel data estimation (model = "panel" in paper_engine()): fixed effects and random effects estimators with automatic Hausman-test-based selection (method = "auto", "fe", or "re"), plus balanced/unbalanced panel diagnostics.
• Added instrumental variables estimation (model = "iv"): two-stage least squares (2SLS) in pure base R, with first-stage weak-instrument diagnostics.
• Added difference-in-differences estimation (model = "did"): treatment x post-period interaction model with parallel-trends diagnostics.
• plot_engine() gains matching plot types for the three new models: a forest plot for panel estimates, a forest plot for 2SLS coefficients, and a parallel-trends plot for DiD.
• Added the academic_salaries example dataset, used in the new panel/IV/DiD vignette sections.

Documentation

• Expanded vignette_tutorial.Rmd with worked examples for panel data, IV, and DiD models.
• Updated paper_engine() and plot_engine() documentation for the new parameters (entity_id, time_id, method, instruments, treatment_var, time_var, treatment_level, post_level).
• Updated README to reflect the six available estimation engines.

OLSengine 1.0.0

• Initial CRAN release: OLS regression, ANOVA/t-tests, and logistic regression, with the integrated “Methodological Customs” diagnostics layer and APA-formatted output tables and plots.