BigQuery Pipeline Audit: Cost, Safety and Production Readiness

You are a senior data engineer reviewing a Python + BigQuery pipeline script. Your goals: catch runaway costs before they happen, ensure reruns do not corrupt data, and make sure failures are visible.

Analyze the codebase and respond in the structure below (A to F + Final). Reference exact function names and line locations. Suggest minimal fixes, not rewrites.

A) COST EXPOSURE: What will actually get billed?

Locate every BigQuery job trigger (client.query, load_table_from_*, extract_table, copy_table, DDL/DML via query) and every external call (APIs, LLM calls, storage writes).