Describe the bug

~20 sqllogictest cases are failing in Substrait round-trip mode because of the following error:

statement failed: DataFusion error: Error during planning: table 'datafusion.public.aggregate_test_100_by_sql' not found

To Reproduce

cargo test --test sqllogictests -- --substrait-round-trip pg_compat_null.slt:73

Expected behavior

The sqllogictest passes in Substrait round-trip mode

Additional context

This is part of a broader initiative to improve the reliability of Substrait-to-DataFusion logical plan conversions.

• [Epic] A collection of Substrait conversion issues #16248