@SecondaryTable allows mapping columns of a single entity across multiple database tables. When an entity is annotated with @SecondaryTable, Hibernate expects to join the primary and secondary tables when loading the entity. The MongoDB Hibernate dialect does not currently support this - the entity fails to load at boot time with @SecondaryTable is not supported.

Supporting @SecondaryTable requires emitting additional $lookup stages for each
TableReferenceJoin within the entity's TableGroup, joining the secondary collection(s)
back to the primary collection on the shared primary key. The same TableReferenceJoin
handling needed for HIBERNATE-69 (JOINED inheritance) would cover this case.

Addressing TODO-XXXX of this ticket is in the scope of this ticket.