fix: clarify event handling in waveform viewer

minimateplus/client.py

@@ -672,9 +672,14 @@ def _decode_a5_metadata_into(frames_data: list[bytes], event: Event) -> None:
         b"Seis Loc:"      at data[735]
         b"Extended Notes" at data[774]
 
-    All frames are concatenated for a single-pass needle search.  Fields already
-    set from the 0C waveform record are overwritten — A5 data is more complete
-    (the 210-byte 0C record only carries "Project:", not client/operator/etc.).
+    All frames are concatenated for a single-pass needle search.
+
+    NOTE: 5A appears to return the compliance config from when the *monitoring
+    session first started*, not per-event config.  This means:
+    - "Project:" from 5A must NOT overwrite a value already set from the 0C record,
+      because 0C carries the correct per-event project name.
+    - "Client:", "User Name:", "Seis Loc:", "Extended Notes" are NOT present in the
+      210-byte 0C record at all, so 5A remains the sole source for those fields.
 
     Modifies event in-place.
     """
@@ -709,13 +714,17 @@ def _decode_a5_metadata_into(frames_data: list[bytes], event: Event) -> None:
         event.project_info = ProjectInfo()
 
     pi = event.project_info
-    # Overwrite with A5 values — they are event-time authoritative.
-    # 0C waveform record only carried "Project:"; A5 carries the full set.
-    if project:  pi.project         = project
-    if client:   pi.client          = client
-    if operator: pi.operator        = operator
-    if location: pi.sensor_location = location
-    if notes:    pi.notes           = notes
+    # "project" comes from 0C (per-event, set during _decode_waveform_record_into).
+    # 5A returns session-start compliance config — its "project" value is NOT
+    # per-event authoritative.  Only use the 5A project as a fallback if 0C
+    # didn't supply one.
+    # client / operator / sensor_location / notes are NOT in the 0C record at all
+    # (confirmed from CLAUDE.md §SUB 5A), so 5A is the sole source for those.
+    if project and not pi.project: pi.project         = project
+    if client:                     pi.client          = client
+    if operator:                   pi.operator        = operator
+    if location:                   pi.sensor_location = location
+    if notes:                      pi.notes           = notes
 
     log.debug(
         "a5 metadata: project=%r  client=%r  operator=%r  location=%r",