Codex did this refactor.
Batch update installs, dependency installs, conflict removals, and replacement removals under one update transaction hook boundary, following pacman's sync transaction model.
Remove the unused pdf-extract dependency and refresh related dependency versions.
- Added `check.rs` to handle package update checks, including logic for determining available updates from remote git repositories and archive listings.
- Introduced `versions.rs` to manage version patterns, comparison logic, and extraction of candidate versions from git refs and archive listings.
- Implemented `hex.rs` for encoding byte arrays to lowercase hexadecimal strings.
SFG545