Introduce full bundle update management: adds bundle_updates module with checking, apply flow, per-cluster locking, subscription inference, and apply helpers for additions/updates/removals (plus unit and e2e test scaffold). Exposes new IPC/API methods (download_package_from_bundle, update_bundle_packages, is_bundle_syncing) and integrates bundle tracking in desktop commands. Adds bundle DAO/entity and migrations to support bundle_packages and bundle_overrides, updates related package/DAO/modpack code, and minor frontend bindings/components/hooks to surface the new functionality. Also adds sea-orm as a dev-dependency for the desktop crate.
Co-Authored-By: Jacob <contact@kath.lol>
