Emergency point release carrying the p2p fork-tolerance fixes for the
2026-07-09/10 network disruptions:

- treat blocks below the fork database window as unlinkable rather than
  invalid, removing the punitive mass-disconnect amplifier that turned
  routine micro-forks into network-wide peer-count collapses (!2064)
- keep peer disconnect notifications decodable: no full-block captures in
  peer-facing exceptions, and tolerate undecodable goodbye messages from
  older peers (!2064, !2065)

No consensus changes; no replay required when upgrading from 1.28.x.