- Add methods to find and clean up obsoleted packages older than a specified TTL (`find_obsoleted_packages_older_than_ttl` and `cleanup_obsoleted_packages_older_than_ttl`) in `libips`.
- Implement a new `CleanupObsoleted` command in `pkg6repo` to handle cleanup operations.
- Update workspace `Cargo.toml` files with unified attributes for better consistency.
- Adjust dependencies (`libips` version patterns, `thiserror` updates) and enhance metadata management for obsoleted packages.
- Enhance repository operations by adding batch processing and robust logging during cleanup.
- Add `obsoleted.rs` module to handle storing, metadata management, and operations for obsoleted packages.
- Implement commands for marking, listing, searching, restoring, exporting, and importing obsoleted packages (`pkg6repo`).
- Enhance `RepositoryError` with `From` implementations for various error types to manage database and serialization-related errors.
- Introduce reusable data structures for obsoleted package metadata and export representation.
- Update `Cargo.toml` and `Cargo.lock` to include new dependencies (`redb`, `bincode`, etc.).
- Document obsoleted package workflow and integration details in `doc/obsoleted_packages.md` for contributors.
- Refactor repository internals to integrate obsoleted package support without disrupting existing workflow.
- Add robust error handling, logging, and pagination for enhanced usability and scalability.
- Replace manual recursive directory scanning with `walkdir` for simplified and efficient file traversal.
- Update dependencies in `Cargo.toml` and `Cargo.lock` to include `walkdir`.
- Enhance code maintainability by replacing redundant logic with streamlined traversal and processing.
