fix: align schema 15 settlement tests and integer validation

tests/test_settlement_cashflow_schema.py

@@ -38,12 +38,12 @@ def test_cashflow_detail_constraints_preserve_blank_categories(tmp_path):
         assert db.execute("SELECT COUNT(*) FROM settlement_cashflow_snapshots WHERE monthly_settlement_id='month-a'").fetchone()[0] == 2
 
 
-def test_init_is_idempotent_and_retains_schema_16_contract(tmp_path):
+def test_init_is_idempotent_and_retains_schema_15_contract(tmp_path):
     path = str(tmp_path / "fresh.sqlite3")
     init_db(path)
     _schema(path)
     with sqlite3.connect(path) as db:
-        assert db.execute("SELECT value FROM schema_meta WHERE key='schema_version'").fetchone()[0] == '16'
+        assert db.execute("SELECT value FROM schema_meta WHERE key='schema_version'").fetchone()[0] == '15'
         assert not db.execute("SELECT 1 FROM sqlite_master WHERE name='asset_snapshot_runs'").fetchone()
         first = db.execute("SELECT COUNT(*) FROM settlement_cashflow_snapshots").fetchone()[0]
     init_db(path)