Add package-build and distribution metadata formats

[andrew]

Add package-build and distribution metadata formats that contain source, binary, build, or runtime dependency relationships.

• Conda: parse dependencies from meta.yaml, meta.yml, recipe/recipe.yaml, and recipe/recipe.yml.
• Arch Linux: parse dependencies from .SRCINFO, .AURINFO, and .PKGINFO.
• Debian: parse package relationships from debian/control and *.dsc.
• BitBake: parse dependency declarations from *.bb and supplements from *.bbappend.
• FreeBSD: parse package metadata and dependencies from +COMPACT_MANIFEST.

Each completed checkbox should identify whether the input is a manifest, lockfile, supplement, or package metadata file and preserve dependency scope where the format distinguishes build and runtime relationships. Add registration, unit tests, fixtures, and README entries.