eventhub/README_PATCH.md

Card-place aggregation regression fix

This patch changes RuntimeEventAggregationService so that it removes only repeated reads of the same physical source record.

Root cause

The parity implementation performed a second reduction by canonical semantic event key. Distinct same-source support records could therefore be collapsed merely because their normalized event content was equal. File-session card-place identifiers such as CARDPLACE-1 may also repeat in separate XML Places sections, so generated identifiers alone are not a safe physical-record key.

Fix

• Prefer raw.rawRecordPath as the physical identity for file-session records.
• Fall back to raw.sourceRowId, raw.supportEventId, externalSourceEventId, event UUID, then canonical key.
• Include domain, type, semantic lifecycle and timestamp so START/END points of one interval remain separate.
• Remove canonical semantic reduction from aggregation.
• Preserve all card/VU evidence for downstream mixing and all CVU/IW evidence for interval reconciliation.
• Add regression tests for repeated CARDPLACE-* identifiers across XML sections and semantically equal but physically distinct place records.