feat(ilm): show already transitioned count

[houseme]

Related Issues

Relates to rustfs/backlog#1478 and rustfs/backlog#1480.

Summary of Changes

• Add skipped_already_transitioned to the manual transition response model with a default of 0 for older servers.
• Show the aggregate count as Already moved in human output.
• Keep marker-like continuation data out of human output.

Verification

• cargo fmt --all --check
• git diff --check
• cargo test -p rustfs-cli --test admin_ilm -- --nocapture
• cargo test -p rustfs-cli test_parse_admin_ilm_transition_run -- --nocapture
• cargo clippy -p rustfs-cli --all-targets -- -D warnings

Impact

The CLI remains compatible with older RustFS servers because the new response field defaults to 0 when absent. No status, wait, cancel, or continuation command behavior is added here.

Additional Notes

This is the CLI companion for the RustFS manual transition already-transitioned counter.