added timing

data_acq_and_processing/common_cpp/ipc/include/shared_types.hpp

@@ -83,6 +83,11 @@ struct ResultBlock {
 struct ResultCollection {
     std::uint64_t collection_id = 0;
     std::uint64_t monotonic_ns = 0;
+    // Wall-clock duration of `process_collection()` for this collection,
+    // measured on the data_processor side with a monotonic clock. Used by the
+    // Python pipeline to report processing-time metrics. Zero is a valid
+    // "unmeasured" sentinel for legacy producers.
+    std::uint64_t processing_duration_ns = 0;
     std::vector<ResultPayload> collection_payloads{};
     std::vector<ResultBlock> blocks{};
 };