1.0.0

First stable release, marking a commitment to the current public API.

Added

• Asynchronous API: async_update_check, UpdateChecker.async_check, and async
  counterparts of the helpers, sharing a single core with the synchronous API.
  Install the optional extra with uv add "update_checker[async]".
• The update notice written to stderr is colorized (yellow) when stderr is a
  terminal, honoring the NO_COLOR and FORCE_COLOR conventions.
• gzip-compressed responses are requested from PyPI, reducing transfer size and
  improving the odds of completing within the request timeout on slow links.
• A py.typed marker (PEP 561) so type checkers consume the bundled
  annotations.

Changed

• The helpers and UpdateChecker methods now take keyword-only arguments;
  update_check(package_name, package_version) remains positional.
• Packaging migrated to uv with a src layout and the uv_build backend.
• The update notice no longer reports version-bump metadata.

Removed

• All runtime dependencies; the package now relies solely on the standard
  library (requests was replaced with urllib).

Fixed

• Release dates are handled as timezone-aware datetimes, fixing incorrect or
  failed date rendering on modern Python.

Security

• The on-disk cache is JSON instead of pickle, removing an arbitrary code
  execution risk (CWE-502) when loading a tampered cache.
• PyPI responses are bounded in size and read time on both paths, and gzip
  decompression is bounded against decompression bombs.
• Package names are URL-encoded in requests.
• Permacache entries with invalid timestamps are ignored rather than crashing
  the caller, and the cache file is written with owner-only permissions.