MapLibplctagStatus now casts the int to libplctag.Status and switches on
named enum members (mirroring AbCipStatusMapper) instead of unverified
magic integers. A strongly-typed Status overload is the canonical path;
the int overload delegates to it. MapPcccStatus is retained with a comment
marking it as the reference mapping for future PCCC-STS inspection.
Tests updated to use Status enum members rather than raw integers.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>