0.2.2

• Drop the proc-macro-error2 dependency in favour of emitting diagnostics via
  syn::Error / compile_error!. This removes the transitive unmaintained-crate
  advisory (https://rustsec.org/advisories/RUSTSEC-2026-0173) and the upcoming
  extern crate proc_macro re-export future-incompatibility. Error messages are
  unchanged.