Changelog for python3-idna: 3.18 -> 3.19
Source: HISTORY.md

## 3.19 (2026-08-XX)

- Restore the `std3_rules` option, which had no effect since changes
  to UTS #46 processing in Unicode 16. Note that `uts46_remap()`
  defaults to enabling STD3 rules, so direct callers will see input
  containing non-LDH ASCII characters rejected again.
- Performance improvements to UTS #46 mapping, particularly for
  ASCII-only domains.
- Test on free-threaded CPython with the GIL disabled and document
  thread safety.
- Expose the Unicode version of the generated tables as
  `idna.unicode_version`, and show it in `idna --version`.
- Add `code`, `text`, `codepoint` and `position` attributes to
  `IDNAError` so that the failed rule and the offending character can
  be identified without parsing the exception message.
- The deprecated `transitional` argument to `encode()` and
  `uts46_remap()` is now completely ignored, and gives a deprecation warning
  for the latter.
- Reject A-labels that are not the canonical Punycode encoding of
  their U-label.
- Fix CONTEXTJ violations raising `IDNAError` instead of
  `InvalidCodepointContext`.
- Consistently raise `IDNAError` for empty labels and non-ASCII bytes
  passed to label helper functions and the incremental codec.
- Add property-based tests, extended fuzzing targets, coverage
  measurement, and CI checks that the data tables match the generator
  output.
- Various code quality and tooling improvements.

Thanks to stefan6419846, LouieLuNZ, and Salvatore Corvaglia for
contributions to this release.