v1.3.0

Fixed

• Make AsyncGzipTextFile.tell() cookies unique per call to avoid collisions that could restore the wrong text position when using seek(cookie).
• Align binary read1() and readinto1() with gzip.GzipFile, including zero-length requests that must not trigger underlying reads.
• Add read-mode binary seek(..., SEEK_END) support to match gzip.GzipFile.
• Support backward seeks on non-seekable binary fileobj inputs by replaying cached compressed input when a rewind is needed.
• Clean up internally opened resources when AsyncGzipBinaryFile.__aenter__() or AsyncGzipTextFile.__aenter__() fails partway through setup.
• Validate that gzip header mtime values fit in the 32-bit field before opening the stream.
• Make text-mode newline tracking match stdlib behavior by reporting observed newline types and preserving that state across seek(tell()) round trips.
• Rework text seek() / tell() handling to use self-contained cookies plus stdlib-compatible plain positions, fixing multibyte, translated-newline, and exact-EOF edge cases without retaining per-cookie cache state indefinitely.
• Fall back to fileobj.name for .name when no explicit filename was provided, matching gzip.GzipFile.

Documentation

• Clarify that text tell() values are opaque cookies intended only for seek(cookie) on the same open stream.

Changed

• Narrow GitHub Actions write permissions so only the coverage-comment job gets elevated access.
• Ignore local mise.toml tool configuration files in git status.

Refactor

• Split the test suite into focused modules for factory, binary, text, file-object, lifecycle, interop, regression, and performance coverage.
• Add contributor guidance to run uv run pre-commit run --all-files before committing so formatting and type-check issues are caught locally.