68c7236acb
This patch enforces that vector indexes can only be created on keyspaces that use tablets. During index validation, `check_uses_tablets()` verifies the base keyspace configuration and rejects creation otherwise. To support this, the `custom_index::validate()` API now receives a `const data_dictionary::database&` parameter, allowing index implementations to access keyspace-level settings during DDL validation. Fixes https://scylladb.atlassian.net/browse/VECTOR-322 Closes scylladb/scylladb#26786