Make the first RAG slice executable without risking production data

The Stage 1 foundation now proves provider contracts with mocks and validates PostgreSQL/pgvector ingestion, approval binding, retrieval, reranking, and idempotency using only synthetic data. Live Bailian validation remains gated on rotating the exposed key.

Constraint: The key shown in chat is compromised and cannot be used or committed

Rejected: Mark Stage 1 complete from mock and offline results | real three-model smoke is still required

Confidence: high

Scope-risk: moderate

Reversibility: clean

Directive: Do not enable real-data ingestion until Stage 3 cloud approval and outbound manifest controls are enforced end to end

Tested: make verify; 41 pytest tests; strict mypy; Ruff; Compose config; pinned image build; empty-volume migration; role denial; two idempotent 20-vector seeds; database restart persistence

Not-tested: Live Bailian calls require a newly rotated key; React product UI is not implemented

backend/app/persistence/__init__.py

@@ -0,0 +1,17 @@
+"""Persistence-level contracts shared by workers and integration tests."""
+
+from .job_queue_sql import (
+    CLAIM_JOB_SQL,
+    COMPLETE_JOB_SQL,
+    FAIL_OR_RETRY_JOB_SQL,
+    HEARTBEAT_JOB_SQL,
+    REAP_EXPIRED_JOBS_SQL,
+)
+
+__all__ = [
+    "CLAIM_JOB_SQL",
+    "COMPLETE_JOB_SQL",
+    "FAIL_OR_RETRY_JOB_SQL",
+    "HEARTBEAT_JOB_SQL",
+    "REAP_EXPIRED_JOBS_SQL",
+]