Status: ready-for-agent

# 06 — Activation framing and copy reduction

## What to build

Profile and reduce avoidable allocations while activation data crosses a seam:
binary frame assembly, header JSON, base64 metadata, CPU/GPU conversion, and
response decompression. Preserve the current binary wire contract and use
zero-copy or pooled buffers only where ownership and lifetime are explicit.

## Acceptance criteria

- [ ] The benchmark identifies copy/allocation cost separately from model and
  network time.
- [ ] Decode hidden-state conversion has no unnecessary float32 round trip.
- [ ] Binary framing avoids base64 for activation bodies and does not retain
  buffers after a request completes.
- [ ] Position/attention metadata is validated and encoded efficiently without
  changing semantic headers or cache positions.
- [ ] A focused test proves byte-for-byte wire compatibility and stable output
  tokens before and after the optimization.

## Blocked by

- 01 — Baseline and profiling harness.