* s3tables: add RenameTable operation
* iceberg: support table rename
* iceberg: test table rename
* s3tables: keep table data in place on rename
rename is catalog-only: drop the source's catalog xattrs in place instead of recursively deleting its directory, which wiped the metadata.json and data files the renamed destination still points at. treat a missing table-metadata xattr as NoSuchTable in GetTable so the soft-deleted source name stops resolving.
* s3tables: test rename preserves data
make the in-memory filer honor recursive data deletion and seed the source table's metadata/ and data/ children, then assert a rename leaves them intact, the source name resolves to NoSuchTable, and the destination resolves to the preserved location.
* iceberg: map rename errors through wrapped manager error
* s3tables: authorize rename destination namespace
rename moved a table into the destination namespace after only checking the source, letting a source-authorized caller place tables in namespaces they don't control. require CreateTable on the destination namespace and bucket before writing.
* s3tables: purge renamed table data on drop
* s3tables: test table data dir derivation
