The headline implementation for issue #160. POST /api/query now gates
direct `bq."<dataset>"."<source_table>"` references behind the registry
and bounds the BQ scan cost behind a configurable cap. Wired through
the same singleton QuotaTracker as /api/v2/scan so daily-byte budgets
are shared across both BQ-touching paths.
Changes in app/api/query.py:
- Add module-level `BQ_PATH` regex matching the 16 syntax variants
verified empirically (fully-quoted, unquoted, mixed quoting,
case-insensitive, inside CTE bodies, multi-path, …).
- Add `bigquery_query` to the SQL keyword blocklist. Closes the
pre-existing function-call backdoor where a user could run an
arbitrary BQ jobs API call against any reachable dataset, bypassing
the registry and RBAC. Wrap views internal to the BQ extractor still
use bigquery_query() — but those run via DuckDB view resolution at
query time, not via user-submitted SQL, so the blocklist doesn't
break them.
- Add `_bq_guardrail_inputs` helper: walks user SQL twice — once for
bare-name matches against accessible registered remote-BQ names
(contributes to dry_run_set), once for direct `bq.X.Y` matches
(gated against `find_by_bq_path` lookups, returns 403 with
structured detail on miss or grant violation).
- Add `_enforce_remote_bq_quota_and_cap` helper: pre-flight
`check_daily_budget` (over-cap → 429), then `with quota.acquire(...)`
wraps a per-path BQ dry-run, sums bytes, raises 400
`remote_scan_too_large` when total > cap.
- Cap default 5 GiB; configurable via `api.query.bq_max_scan_bytes`
in /admin/server-config (next phase wires the UI).
- Post-flight `record_bytes` against the user's daily counter.
- Module-level imports of `_bq_dry_run_bytes`, `_build_quota_tracker`,
`get_bq_access` so tests can monkeypatch via `app.api.query.<name>`.
Tests:
- All 23 RED tests from the previous commit now pass (regex matrix,
blocklist with detail-string assertion, RBAC unregistered/admin-bypass,
guardrail dry-run-called/over-cap-rejected, quota pre-flight 429).
- mock_dry_run fixture stubs both `_bq_dry_run_bytes` and `get_bq_access`
so guardrail tests don't require a live BQ project.
- Quota test uses `admin1` (the seeded_app fixture's actual user id, not
`admin`).
Smoke: 887 passed across query/bq/admin/extractor/registry/quota
domains. No regressions.
896c43c7a2