Pure-function-friendly reference to a pooled buffer. The pool itself
collects Ref structs that include splice metadata; the public ref
is the byte-cost + opaque payload that the eviction selector needs
— see selectBuffersToEvict in ./eviction-policy.
Pure-function-friendly reference to a pooled buffer. The pool itself collects
Refstructs that include splice metadata; the public ref is the byte-cost + opaque payload that the eviction selector needs — seeselectBuffersToEvictin./eviction-policy.