Function initialize_transient 

pub fn initialize_transient<E, F>(
    connection: &Connection,
    busy_timeout: Duration,
    schema: SchemaVersion,
    initialize: F,
) -> Result<(), InitializationError<E>>
where
    F: FnOnce(&Transaction<'_>) -> Result<(), E>,

Initialize a transient database with the same atomic schema-marker contract.

No filesystem lock or WAL promotion is performed because the connection is not shared across processes. A process-local lock serializes connection configuration, readiness inspection, and first use of named shared-memory databases because shared-cache schema reads conflict with schema creation. The callback follows the same transaction-local effects and at-most-once invocation contract as initialize_file.