Revive coverpy for Python 3

[matteing]

Summary

• rebuild coverpy as a typed Python 3.10+ package with a modern src/ layout
• add richer search, catalog lookup, UPC lookup, and CLI APIs while preserving legacy names
• replace legacy setuptools/requirements/Make tooling with pyproject.toml, uv, uvx, and uv.lock
• replace Travis CI with GitHub Actions and trusted PyPI publishing
• remove the committed .DS_Store and other obsolete project files

Impact

This is the 1.0 revival of the original 2016 package. Existing convenience names remain
available, while new users get typed APIs, richer metadata, and a uvx coverpy command.

Validation

• 51 tests pass on Python 3.14
• 97% branch-aware coverage
• Ruff formatting and linting pass
• strict mypy passes
• wheel and source distribution build successfully
• both distributions pass smoke tests and Twine metadata checks
• live iTunes Search API query succeeds