Give the protocol example and vocabulary one owner

[MongLong0214]

First step of the README/canonical-docs restructure: move the fact ownership before touching the README's shape, so no gate is lost on the way.

Why this was the blocker

docs/protocol.md stated the situation itself:

The worked example that uses the full vocabulary stays in the README, in every language, because it is also a conformance fixture.

That is the direct reason the README reads as a specification summary rather than a product page. The gate lived on four translated copies, so the content had to live there too — 44 lines of complete record and vocabulary table, repeated per language, each a place for it to drift.

What changed

The gate moves, and the content follows it.

spec/verify.sh                       README.md + README.*.md  →  docs/protocol.md
spec/schema/readme-vocab-check.mjs   →  protocol-doc-vocab-check.mjs, same target

The fixture is found by a marker, not by position. The old rule took the last ```text block in the file:

const m = [...md.matchAll(/```text\n([\s\S]*?)\n```/g)].at(-1);

A positional rule cannot say what it owns. Adding an example anywhere below it silently moves the contract onto a different block, and the check keeps passing. Now:

<!-- SPEC-FIXTURE:11-readme-example -->

A missing marker is a failure, not a quiet retarget.

Each README keeps a small record example and a link. That example is illustrative rather than the fixture, so the four translations no longer have to carry the same forty lines byte for byte.

README.md      648 → 616 lines
README.ko.md   546 → 514
README.ja.md   552 → 520
README.zh-CN   532 → 500

Verification — three negative controls at the new owner

Each was applied to docs/protocol.md, spec/verify.sh run, then restored:

mutation	result
Certainty: firm → Certainty: high	FAIL: 대표 예제가 픽스처와 다르다 — and high is a value our own rejection fixtures carry
delete the Expires: row	FAIL: SPEC에 있으나 표에 없음: Expires
delete the marker	FAIL: no <!-- SPEC-FIXTURE:11-readme-example --> marker
restore	OK: 32 fixtures + protocol example sync + vocab table

Also: 101 tests across readme, release-publish-prerequisites and release-tag-binding; check-readme-numbers.mjs exit 0; the CI workflow digest re-locked after the comment edit.

Scope

The evidence block is the other four-way duplicate and is untouched here. check-readme-numbers.mjs still owns it across all four READMEs; moving it is its own change with its own negative control, and mixing the two would blur which gate is proving what.

No product behaviour changes.

[github-actions]

CommitLore — record lint

Trailers: clean — 2 commits in origin/main..65721f64600fcb91733f8694913713d469852f77
Active constraints: not read — commitlore: git log --follow accepts exactly one pathspec, so renames are not followed for 9 paths; query one path at a time to follow its rename chain (9 changed paths)

_{Trailer violations fail this check. Active constraints are informational — they are what the repository already decided, not a verdict on this PR.}