Per #3740 review: many short strings (e.g. a tool result whose content array holds thousands of small text blocks) could sum past MAX_REPLICATED_PAYLOAD_BYTES without any individual field crossing the per-string floor, so the helper exited the truncation loop and shipped an oversized frame — the relay close/reconnect loop the helper was meant to prevent.
Replace the string-only truncation pass with a single walker that head-truncates strings AND head-clips arrays in one descent, driven by a concrete SHRINK_PASSES schedule that tightens both axes together. The final pass clamps every string to 64 B and every array to one element, so any payload converges. Add direct unit tests for shrinkForReplication covering: identity for small values, single-giant-string clamp, many-short-strings array clamp (no field above floor), and discriminator preservation on a fully-shrunk payload.
roboomp
378bc1aeca