fix: preserve schema 15 compatibility for v0.1.8

tests/test_settlement_draft_docs.py

@@ -174,7 +174,7 @@ def test_settlement_draft_runtime_cancel_and_recovery_contract() -> None:
     for clause in ("cancel_settlement_draft(draft_id, expected_version, cancelled_by, reason, db_path=None)",
                    "active", "nonempty", "cancelled_by", "cancellation_reason", "cancelled_at",
                    "approval_fingerprint", "approval_version", "version", "updated_at", "BEGIN IMMEDIATE",
-                   "retained", "account_valuations", "asset_snapshot_runs", "account_snapshot",
+                   "retained", "account_valuations", "asset_snapshot_runs", "asset_snapshots",
                    "rollback", "no-write", "completed", "cancelled", "fresh create key",
                    "same create key", "latest prior run", "correction_of_run_id", "correction_reason",
                    "tests/test_settlement_draft_correction_contract.py"):
@@ -207,7 +207,7 @@ def test_settlement_cashflow_model_documents_schema_and_legacy_reproduction(tmp_
     names = {
         "asset_snapshot_runs": ("settlement_month", "currency", "income_total", "expense_total", "net_cashflow", "total_assets", "total_liabilities", "net_worth", "cashflow_policy_json", "aggregation_version", "snapshot_schema_version", "source_snapshot_json"),
         "settlement_drafts": ("cashflow_policy_json", "aggregation_version"),
-        "settlement_cashflow_snapshots": ("id", "settlement_run_id", "cashflow_kind", "category", "subcategory", "amount", "transaction_count", "currency"),
+        "settlement_cashflow_snapshots": ("id", "monthly_settlement_id", "settlement_run_id", "cashflow_kind", "category", "subcategory", "amount", "transaction_count", "currency"),
     }
     database = tmp_path / "synthetic-doc-schema.sqlite3"
     init_db(str(database))
@@ -220,7 +220,12 @@ def test_settlement_cashflow_model_documents_schema_and_legacy_reproduction(tmp_
     reproduction = _comprehensive_section(doc, "### Comprehensive snapshot evidence inputs")
     for field in ("source_snapshot_json", "transactions", "assets", "transaction_date", "originalcashflow_kind", "applied_amount", "valuation_id", "valuation_date", "authority_source", "cashflow_policy_json", "legacy", "NULL"):
         assert field in reproduction, field
-    for constraint in ("ON DELETE RESTRICT", "UNIQUE", "transaction_count > 0", "idx_settlement_cashflow_snapshots_run"):
+    for constraint in (
+        "ON DELETE RESTRICT", "UNIQUE", "transaction_count > 0",
+        "idx_settlement_cashflow_snapshots_run", "exactly one parent",
+        "(settlement_run_id,cashflow_kind,category,subcategory,currency)",
+        "(monthly_settlement_id,cashflow_kind,category,subcategory,currency)",
+    ):
         assert constraint in doc, constraint