Concrete implementation of the catalog object hierarchy declared by core::interface::catalog. Owns the on-disk
representation of namespaces, tables, views, flows, identities, policies, sequences, tokens, tests, and the system
objects ReifyDB self-hosts; resolves names through the resolved-name machinery; and provides the materialized
views that the engine reads to plan and execute queries.
Catalog reads ride on a regular transaction; catalog writes go through the admin transaction so DDL and identity mutations are isolated from concurrent OLTP traffic and emit their own change records. Bootstrap installs the system namespace and the seed identities the rest of the system depends on; vtable exposes catalog state to RQL as queryable virtual tables.
Invariant: persisted catalog ids (namespace id, table id, identity id, etc.) are stable across reboots; ephemeral per-boot ids exist for in-memory resolution but never round-trip through storage. Mixing the two leaves dangling references when the process restarts.