Dead fields left over from the original parser schema: srccallsign,
dstcallsign, origpacket, header, body, alive, posambiguity,
symboltable, symbolcode, messaging. None are declared in the Packet
schema, none are read anywhere in lib/ or test/, and Packet.strip_dead_fields/1
already removed them from attrs before insert.
In environments where ConsolidatePacketsColumns (20260220230000)
already DROP/RECREATEd the table without these columns the migration
is a safety-net no-op thanks to IF EXISTS; otherwise it ALTERs the
parent partitioned table and Postgres cascades to all partitions.