Track and surface partial modpack download failures across core and frontend. Adds a PartialModpackInstall error and counts failed/attempted downloads in the mrpack flow, returning an error if some files failed. Frontend download pipeline now runs parallel downloads that return per-item results, reports/logs failures, and exposes retry/continue UI in onboarding.
Backend robustness improvements: deduplicate concurrent package inserts by reusing existing row on unique-hash constraint, detect hard-link collisions and verify hashes before skipping or erroring, and return meaningful errors when partial installs occur.
Other changes: propagate richer error context when stamping migrated cluster created_at, invalidate relevant queries after migration, make settings writes awaitable and update the query cache optimistically, add queryClient usage in version-migration hook, and various type/bindings updates to reflect the new PartialModpackInstall error. These changes improve reliability and UX during batch package installs and onboarding downloads.
