feat(gateway): DataSink.update_write_status Postgres by timestamp+model_id (C3); drop unused metadata param

tests/unit/io/test_data_sink_status.py

@@ -0,0 +1,72 @@
+from unittest.mock import MagicMock
+
+import pytest
+
+from ingestor.engines.write import WriteResult
+from ingestor.io.data_sink import DataSink
+
+
+def make_sink():
+    postgres = MagicMock()
+    connection = MagicMock()
+    postgres.engine.begin.return_value.__enter__.return_value = connection
+    sink = DataSink(data_manager=MagicMock(), postgres=postgres)
+    return sink, connection
+
+
+@pytest.mark.asyncio
+async def test_update_write_status_targets_model_row():
+    sink, connection = make_sink()
+    cmd = {
+        'schema': 'sientia_data',
+        'table_name': 'pred_m1',
+        'model_id': '1',
+        'timestamp': '2026-07-13T00:00:00Z',
+    }
+    result = WriteResult(ok=True, status='ok', opc_status_code='Good', message='')
+
+    await sink.update_write_status(cmd, result)
+
+    assert connection.execute.call_count == 1
+    stmt, params = connection.execute.call_args[0]
+    sql = str(stmt)
+    assert 'update' in sql.lower() and 'write_status' in sql.lower()
+    assert 'sientia_data.pred_m1' in sql
+    # values must be bound params, never interpolated into the SQL text itself
+    assert params == {'status': 'ok', 'timestamp': '2026-07-13T00:00:00Z', 'model_id': '1'}
+    assert 'ok' not in sql
+    assert '2026-07-13T00:00:00Z' not in sql
+
+
+@pytest.mark.asyncio
+async def test_update_write_status_rejects_bad_schema():
+    sink, connection = make_sink()
+    cmd = {
+        'schema': 'a; DROP TABLE x',
+        'table_name': 'pred_m1',
+        'model_id': '1',
+        'timestamp': '2026-07-13T00:00:00Z',
+    }
+    result = WriteResult(ok=False, status='error', opc_status_code='Bad', message='x')
+
+    with pytest.raises(ValueError):
+        await sink.update_write_status(cmd, result)
+
+    connection.execute.assert_not_called()
+
+
+@pytest.mark.asyncio
+async def test_update_write_status_rejects_bad_table_name():
+    sink, connection = make_sink()
+    cmd = {
+        'schema': 'sientia_data',
+        'table_name': 'pred_m1; DROP TABLE x',
+        'model_id': '1',
+        'timestamp': '2026-07-13T00:00:00Z',
+    }
+    result = WriteResult(ok=False, status='error', opc_status_code='Bad', message='x')
+
+    with pytest.raises(ValueError):
+        await sink.update_write_status(cmd, result)
+
+    connection.execute.assert_not_called()