Function preflight_public_ddl_statement 

pub fn preflight_public_ddl_statement(
    conn: &Connection,
    request: &SqlStatementRequest,
) -> Result<(), StatementRunError>

Validate a public DDL statement through the same parser and reserved-object authorizer as run_ddl_statement without executing it. The cluster DDL coordinator uses this preflight before installing its action-recording authorizer; SQLite supports one authorizer per connection, so the real execution then runs through run_preflighted_ddl_statement while the recorder observes the exact DROP/ALTER/index actions.