Status: IN
CDC event semantics are determined by reconstruction heuristics rather than explicit markers: insert vs update is distinguished by checking whether old_value is None, tombstones are reported as None values indistinguishable from missing data in conflict records, and snapshots use a sentinel sequence number (-1) to distinguish bootstrapped state from real events.
Event type, deletion state, and bootstrap origin are all inferred from value-level conventions
Depends on (SL): cdc-determines-insert-vs-update-by-old-value, tombstone-reported-as-none-in-conflict, cdc-snapshot-uses-sentinel-sequence-number