Persisted metadata for one Jido journal thread.
Entries remain append-only in squidie_journal_entries; this row tracks the thread revision and metadata needed to reconstruct the Jido thread envelope.
squidie_journal_entries
@type t() :: %Squidie.Persistence.JournalThread{ __meta__: term(), created_at_ms: term(), id: term(), inserted_at: term(), metadata: term(), rev: term(), updated_at: term(), updated_at_ms: term() }