[saadmk11]

2.0.0

Breaking changes

• Python 3.11 or newer is required. Support for Python 3.6–3.10 has ended.
• Standard-library and typing names are no longer part of the public API.
  Import them directly from the standard library.
• Output, state, and environment files now store raw values. Literal %, %0A,
  carriage returns, line breaks, Unicode, and whitespace are preserved instead
  of being percent-encoded.
• Job summaries preserve literal Markdown, including %25, %0D, and %0A.
  These sequences are no longer decoded.
• Log commands escape message text so embedded line breaks cannot introduce
  additional commands. echo() continues to print raw text.
• Invalid file-command names and stop tokens raise ValueError before writing.
  File-command names must be nonempty and exclude =, <<, CR, LF, and NUL.
  Malformed pending environment records raise ValueError.
• PATH entries containing NUL are rejected. Subprocess failures now propagate
  as subprocess.CalledProcessError.

Added

• Live, read-only environment access through vars, WorkflowVariables,
  GitHubVariables, and RunnerVariables. Text values remain strings; flags
  have explicit boolean values. is_github_action() detects GitHub Actions.
• get_boolean_input() and get_multiline_input(), with required-input,
  whitespace, and empty-line options. get_user_input() gains optional
  required and trim_whitespace arguments; its defaults are unchanged.
• set_command_echo() for runner command diagnostics and fail() for an error
  annotation followed by exit status 1.
• add_problem_matcher() and remove_problem_matcher() for tool annotations.
• declare_file_artifact(), declare_oci_artifact(),
  get_workflow_artifacts(), and immutable ArtifactSubject metadata. These
  require runner support and record identities without uploading files or images.
• Text PathLike support and optional strict=True validation in
  add_system_path().
• Inline type annotations and py.typed for installed-package type checking.

Fixed

• Multiline file records use unique, collision-checked delimiters and UTF-8
  without losing leading BOM characters or trailing newlines in values.
• Pending environment reads handle simple and multiline records, leading UTF-8
  BOMs, empty values, and duplicate names. The last value for a name wins.
• get_env() preserves an empty process value and returns None for missing
  local values. get_workflow_environment_variables() returns an empty
  dictionary when the GITHUB_ENV path is unset or empty.
• group() closes its log group and stop_commands() restores command
  processing when the context body raises. Generated stop tokens use UUID4.
• Console output is flushed. Subprocess mode uses the current Python interpreter
  and standard input, avoiding shell interpretation, command-line length limits,
  and platform-specific echo behavior.
• PATH writes add missing record terminators while preserving existing batches.
• Input names containing spaces can use underscore-separated INPUT_* keys;
  an existing literal key still takes precedence. Hyphens remain unchanged.

Development and releases

• Move to a src package layout, pyproject.toml, uv builds and publishing,
  and locked development dependencies. The package has no runtime dependencies.
• Use Python 3.15 for development. CI covers Python 3.11–3.15 on Linux, Windows,
  and macOS, with Ruff, strict mypy, and full statement and branch coverage.
• Check clean wheel/source installs, installed typing, and upgrades from 1.1.0.
  A feature showcase checks cross-step values and action main/post state.
• Publish with PyPI Trusted Publishing after validating the release tag and
  distributions. Verify the published package in a clean environment.

Upgrading from 1.1.0

1. Update workflows to Python 3.11 or newer, then upgrade the package to 2.0.0.
2. Pass raw values to file writers and job-summary helpers. Remove workarounds
   that manually encode or decode percent sequences and line breaks.
3. Use echo() inside stop_commands() when printing text that must remain
   literal, including command-looking text.
4. Check custom file-command names and stop tokens against the validation rules
   in the README.
5. Remove the deprecated use_subprocess argument from set_output() and
   save_state(). It remains accepted with a DeprecationWarning; both
   functions always write runner files.

Existing package functions, public call signatures, the mutable
COMMANDS_USE_SUBPROCESS setting, and event-payload caching remain available.
set_env() and PATH changes still apply to later steps; they do not change the
current Python process.

closes: #17
closes: #20
closes: #21
closes: #24