Harden chunk plan cache storage and reuse

internal/core/source/chunk_plan.go

@@ -207,7 +207,34 @@ func cloneJSONMap(values map[string]any) map[string]any {
 	}
 	cloned := make(map[string]any, len(values))
 	for key, value := range values {
-		cloned[key] = value
+		cloned[key] = cloneJSONValue(value)
 	}
 	return cloned
 }
+
+func cloneJSONValue(value any) any {
+	switch typed := value.(type) {
+	case map[string]any:
+		return cloneJSONMap(typed)
+	case []any:
+		cloned := make([]any, len(typed))
+		for i := range typed {
+			cloned[i] = cloneJSONValue(typed[i])
+		}
+		return cloned
+	case json.RawMessage:
+		return append(json.RawMessage(nil), typed...)
+	case []byte:
+		return append([]byte(nil), typed...)
+	case []string:
+		return append([]string(nil), typed...)
+	case map[string]string:
+		cloned := make(map[string]string, len(typed))
+		for key, item := range typed {
+			cloned[key] = item
+		}
+		return cloned
+	default:
+		return value
+	}
+}