Fix ops write pressure integration fixture

Author: xvhuan

backend/internal/repository/ops_write_pressure_integration_test.go

@@ -22,6 +22,7 @@ func TestOpsRepositoryBatchInsertErrorLogs(t *testing.T) {
 			RequestID:    "batch-ops-1",
 			ErrorPhase:   "upstream",
 			ErrorType:    "upstream_error",
+			Severity:     "error",
 			StatusCode:   429,
 			ErrorMessage: "rate limited",
 			CreatedAt:    now,
@@ -30,6 +31,7 @@ func TestOpsRepositoryBatchInsertErrorLogs(t *testing.T) {
 			RequestID:    "batch-ops-2",
 			ErrorPhase:   "internal",
 			ErrorType:    "api_error",
+			Severity:     "error",
 			StatusCode:   500,
 			ErrorMessage: "internal error",
 			CreatedAt:    now.Add(time.Millisecond),