Function validate_public_ddl_poststate 

pub fn validate_public_ddl_poststate(
    conn: &Connection,
    changed_rows: usize,
    pre_tables: &HashSet<String>,
    post: &[ReplicatedTableSchema],
    declared_tables: &[String],
    ddl_only_message: &'static str,
    ran_drop_table: bool,
) -> Result<(), BookkeepingError>

Validate the producer-side post-state shared by standalone deploy migrations and public SQL DDL. Call this from the schema transaction’s final validation hook, before any outcome/journal tail and before COMMIT, so every refusal rolls the schema and its host bookkeeping back as one unit.