refactor: move subcommands to separate modules

[messense]

No description provided.

[Copilot]

Pull request overview

Refactors the CLI implementation by moving several subcommands and helpers out of main.rs into dedicated modules, and introduces a shared test helper for resolving test-crates paths.

Changes:

• Extracted CLI subcommand implementations (build/publish/sdist/develop/pep517, etc.) into src/commands/*.
• Added test_crate_path helper and updated tests to use it instead of hard-coded test-crates/... paths.
• Adjusted SBOM fallback code to silence unused-variable warnings when the sbom feature is disabled.

Reviewed changes

Copilot reviewed 14 out of 14 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/test_utils.rs	Adds a shared helper to resolve paths under test-crates for tests.
src/sbom.rs	Updates non-sbom feature branch to mark parameters as unused.
src/pyproject_toml.rs	Uses test_crate_path in tests to locate fixture pyproject.toml.
src/metadata.rs	Uses test_crate_path in tests and avoids hard-coded fixture paths.
src/main.rs	Replaces inlined subcommand logic with calls into commands::* modules.
src/lib.rs	Exposes test_utils module for tests via #[cfg(test)].
src/commands/mod.rs	New command module hub plus shared CLI helpers/options.
src/commands/utils.rs	New shared helpers for building/unpacking sdists.
src/commands/build.rs	Extracted build command implementation.
src/commands/publish.rs	Extracted publish command implementation.
src/commands/sdist.rs	Extracted sdist command implementation.
src/commands/develop.rs	Extracted develop command implementation and venv detection.
src/commands/pep517.rs	Extracted PEP517 subcommand enum and dispatch function.
src/build_options.rs	Updates tests to use test_crate_path for fixture manifests.