Switched the project to a uv-native workflow with uv_build, dependency groups, and a refreshed lockfile.
Modernized pyproject.toml metadata and tool configuration for the current package layout.
Refactored the CLI implementation with stronger typing, centralized constants, and a canonical alphafold_file_url helper while keeping backward compatibility for the older misspelled helper name.
Added explicit typing exports in affetch.__init__ and affetch.__version__.
Replaced the placeholder test module with executable smoke tests for core parsing and file-writing behavior.
Rewrote the README, contributing guide, and MkDocs site to focus on real install, usage, development, and reference workflows.