Runs the appropriate assumption checks for a chosen statistical test (Shapiro-Wilk or Anderson-Darling for Normality, Levene or Brown-Forsythe for equal variance, QQ-plot for residuals, Cook's D for influence, expected-cell- count rule for chi-squared) and reports pass/fail per assumption with the evidence (test statistic + p-value) and the consequence if the assumption fails. Use whenever the user is about to run a parametric test, has just run one and wants to validate, or asks 'are the assumptions met?'.
