[boyfeiyu]

Custom Item subclasses currently need to override a private method and import private types to filter tracebacks while retaining pytest's standard failure formatting.

This adds Node.traceback_filter and exports pytest.Traceback and pytest.TracebackEntry. The public method delegates to _traceback_filter by default, so existing overrides and the filtering provided by Function and collectors continue to work. An explicit public override takes precedence when both names are overridden. Tests cover Python and non-Python items, collectors, traceback styles, --full-trace, legacy overrides and special failures.

Related #15297. This addresses the public customization and typing API; default hidden-frame filtering is unchanged. It does not implement a global traceback hook.

Validation on macOS arm64 / CPython 3.13.18:

• Related regression suite: 1345 passed, 25 skipped, 5 xfailed.
• Node tests: 66 passed. The corresponding baseline control fails for public overrides and passes for the legacy override.
• All applicable pre-commit hooks passed, including mypy.
• Strict Sphinx HTML build passed without warnings.

The full platform/Python matrix has not been run locally.

• Documentation and tests included.
• Changelog entry and AUTHORS entry included.
• AI agents credited in the commit's Co-authored-by trailer.
• Allow maintainers to push and squash when merging my commits.