Normalization of per catalog values?

[pepijnve]

Similar question to duckdb/ducklake-web#45. Since next_catalog_id and next_file_id are stored per snapshot table row value it's not 100% clear how you're supposed to manage these.

• If there are multiple snapshots in the database which counter do you use and increment? Only that of the latest?
• When creating a new snapshot, do you initialize these to zero or to the value from the most recent snapshot so far?

These two counters seem to be catalog wide values. If that's correct would it not be better to store them in normalized form?