## What and why

<!-- What this changes, and the ruling, issue or design section it carries out. -->

Closes #

## Acceptance

The **Acceptance** check runs on this pull request by itself -- amd64, aarch64, riscv64, the PC
stick loaded high, test-32 -- and `master` takes nothing that has not passed it. Note here
anything it does not cover:

- [ ] `logs/<TS>/PROTOCOL.md` for the head commit: `scripts/nightly.sh protocol`, run by hand,
      its `logs/` and `experiments/bare_metal/runs/` committed (#135). The check refuses a head
      without one, or with one for another tree.
- [ ] Logs from other runs made by hand are committed in `logs/`, if any
- [ ] Hardware this was tried on, if any:

## The record

- [ ] `docs/fabric/FABRIC-3.md` has the ruling and what was built, if this is design work
- [ ] `CHANGELOG.md`, if it is a milestone
- [ ] Nothing in this PR is a fix nobody asked for (`.claude/CLAUDE.md`, Hard Rules)