Compares the minimum admiral version required by the layers used in the IR against the installed admiral version. Absence of admiral is not an error: rendering is static and only execution is blocked.
Value
A character vector of problem messages (empty when compatible); the vector carries a `note` attribute when admiral is not installed.
Examples
spec <- mock_spec_adsl()
ir <- classify_variables(spec, "ADSL", backend = "rules")
check_admiral_compat(ir)
#> character(0)