Submit async batch DuckDB job

Ordered list of queries to run on the container

Compute resource request shared by the DuckDB cluster and E2B sandbox paths.

Defaults are sized for the DuckDB cluster. Non-DuckDB callers must check model_fields_set before reading cpu/memory, otherwise the DuckDB defaults will be used for other engines — see defapi.config.e2b.select_e2b_sandbox_tier for an example.