added timing

python_app/models/dataset_model.py

@@ -80,5 +80,8 @@ class ResultCollection:
 
     collection_id: int
     monotonic_ns: int
+    # Wall-clock nanoseconds spent by the data_processor on `process_collection`
+    # for this collection. Zero means the producer did not report a measurement.
+    processing_duration_ns: int = 0
     collection_payloads: list[ResultPayload] = field(default_factory=list)
     blocks: list[ResultBlock] = field(default_factory=list)