v0.12.1

Fixed

• StrictIso starts with char_conversion=on and reports unsupported flags with the ISO
  domain_error(prolog_flag, Flag). Flag enumeration preserves its initial values across redo.
• ISO module interface reader directives prepare body state without changing the parsing of
  later interface directives.
• Runtime grammar variables are called when execution reaches them, including alternatives,
  conditions, and unreachable branches; conditional recognition does not bind variable alternatives.
• Generated constant construction runs in a separate method, avoiding floating-constant
  corruption observed in a large NativeAOT installation on macOS Arm64.
• Exceptions preserve cyclic terms while unwinding to catch/3, so number_chars/2 and
  number_codes/2 report type_error(list, Culprit) for cyclic lists with the original
  cyclic structure intact, instead of replacing the error with representation_error(cyclic_term).
  Explicit throw/1 balls also retain cycles.

Added

• 29 further standard-only review cases covering grammar controls, exception scope, variable
  sharing, and flag snapshots. The 125-case fixture runs through managed, generated, cross-path,
  and NativeAOT execution, with additional regressions for flags and module reader state.