Add logging checkpoints with Data Tables

Nobody can see how many records actually made it through each stage of the ingestion run — and you don't want to reshape the main pipeline just to find out. A side-branch audit trail tracks progress without disrupting the data flow.

Import the starter, create an execution_log table, and add Data Table insert nodes as side branches off HTTP Request, Transform Data, and Format Output. Finish with Get row(s) to verify that three checkpoint rows land in the table.