Add CLI version flag

[rupayon123]

Summary

• Add -v / --version support to the modelinfo CLI using importlib.metadata.version.
• Fall back to the package version when running directly from source without installed metadata.
• Add a CLI regression test for the version action.

Validation

• /Users/rupayonhaldar/.cache/codex-runtimes/codex-primary-runtime/dependencies/python/bin/python3 -m pip install -e .[dev]
• PYTHONPATH=src /Users/rupayonhaldar/.cache/codex-runtimes/codex-primary-runtime/dependencies/python/bin/python3 -m pytest tests/test_cli.py tests/test_constraints.py
• /Users/rupayonhaldar/.cache/codex-runtimes/codex-primary-runtime/dependencies/python/bin/python3 -m ruff check src/modelinfo/cli.py tests/test_cli.py

Closes #13

[rupayon123]

Rebased this onto current main and reran the local checks:

• python -m pytest — 15 passed
• python -m ruff check . — passed

The branch is ready for review now.

[pipe1os]

Thank you for your contribution!

the code is good but evaluating package_version()in parse_args()forces importlib.metadata.version to run on every CLI invocation. Since it hits the disk to find package metadata, this adds ~30ms to the startup time.

I pushed a commit replacing the version string evaluation with a custom argparse.Action class. This defers the import and version lookup until the user actually passes the --version flag so the CLI tool remains fast.