WebSocket reconnect catch-up only checked the number of missing events, then loaded and decoded the whole replay range before sending it. A handful of events with large tool payloads could allocate gigabytes and OOM the server.

Before replaying, run a SQL preflight that counts the events in the range and sums their serialized payload bytes with octet_length(). If the range is over the existing row limit or an 8 MiB byte budget, fall back to the fresh snapshot path. Applies to both thread and shell subscriptions.

Authored by @rcawston. Review, octet_length fix, and merge by Claude Fable 5.1 in Claude Code on behalf of @t3dotgg.