Buffer

Append-only text store behind the named, persistent Probe channels — its only consumer — held as immutable segments. Content is never dropped; the channel stays unbounded.

A single StringBuilder puts two O(channel) operations on the WRITER's thread, which is a patch handler's, i.e. a tick thread: the doubling realloc, and the Latin-1 -> UTF-16 inflate that the first non-ASCII char forces over the whole array. Freezing at SEGMENT_CHARS bounds both by that constant.

The size check runs AFTER the append, so no write is split: every segment ends at the newline appendLine put there, and a consumer splitting segments into lines never sees a torn one.

A runaway channel is reported to Constants.LOG and nowhere else: Probe's consumer is script CODE, so an injected note would land in whatever parses the result, and a cap would make every read ask "was that all?".