- tests/test_bq_cost_guardrail.py: assert fail-open warning is logged
(test previously only proved fail-open doesn't crash; review note:
warning is the only operator-visible signal of the silent failure).
- extractor._wrap_admin_sql_for_jobs_api: docstring no longer claims
DuckDB-flavor SQL is rejected — the function performs no inner-SQL
validation; the v24 migration + register-time validator are the
real enforcement points.
- extractor.materialize_query: safe_path uses _escape_sql_string_literal
instead of inline replace, for one-place-to-update consistency.
- extractor: import hashlib hoisted to module-level imports.
Pre-fix, materialize ran the admin source_query as 'COPY (sql) TO parquet'
through the DuckDB BQ extension session. The extension defaults to the
BQ Storage Read API for bq.<ds>.<tbl> references, which rejects views
('non-table entities cannot be read with the storage API'). The fix
always wraps admin SQL into bigquery_query('<billing>', '<inner>') so
COPY uses the BQ jobs API uniformly for tables and views.
Cost guardrail dry-run now operates on the inner SQL (BQ-native), so
the BQ Python client parses it and the cap engages — pre-fix the dry-run
hit 'Table-valued function not found: bigquery_query' and fail-opened.
