docs(release): pin the executable editor recipe to the published CLI and MCP server version

[Rul1an]

Measured defect

Measured on origin/main 2b1339e309c7027d63970dd5913b28b3bab36409, published release v5.5.2.

docs/guides/editor-mcp-recipe.md is an executable launch-facing recipe, but its two prerequisite commands are floating:

cargo install assay-cli --locked
cargo install assay-mcp-server --locked

The repository already requires cargo install assay-cli --version $PUBLISHED_VERSION --locked across the outward release surface. The editor recipe is selected by that gate but is not one of its pinned install-command obligations, and scripts/ci/check-editor-mcp-recipe-truth.sh currently requires the floating forms. A later crates.io publication can therefore silently change the binaries installed by the flagship recipe while the recorded Claude/Codex launch evidence remains bound to v5.5.2.

This is not a current wrong-version claim: today the floating commands resolve to the published release. It is a self-arming release-integrity defect and must close before launch communication.

Parent decision: #2739 chooses to keep Darwin MCP archives unsupported and retain an exact crates.io route.

Behavioral DoD

• RED first: show that a stale --version, a missing --version, and a second floating install can currently survive the relevant guards.
• The plugin-install section contains exactly one published-version-pinned install for assay-cli and exactly one for assay-mcp-server, both with --locked.
• cargo install --path crates/assay-mcp-server --locked remains the intentionally unpinned source-checkout route.
• Published-version truth comes from .github/assay-release-tag through the existing reader, never a new literal.
• One guard owns the exact install-command rule. The editor transport guard must not reimplement a second version rule that can drift; retain its stdio/protocol and executable-section obligations.
• Comments, prose, a command in another section, duplicate commands, and source-path installs cannot satisfy the published-install obligation.
• A release-pin change selects the guard locally and in CI.
• Focused self-tests, actual guards, git diff --check, and public-string inspection are green.

Non-claims

This does not add Darwin archives, Apple signing/notarization, MCPB support, host discovery, marketplace discovery, or a new release. It does not retrofit immutable v5.5.2 assets. It only makes the documented crates.io journey identify the same published version the launch evidence measured.

[Rul1an]

@GrokBt bounded writer resume: PR #2748 is still frozen at exact head ab33694. The final reviewed helper chain is available at codex/2748-close-fence-v2 head d1abe11.

If your owned worktree and live PR still match ab33694, verify the direct ancestry/five-file scope, fast-forward only, rerun 25/25 + 38/38 + 95/95 and the named marker/empty-output mutations, then push once and freeze. Stop on any drift, conflict or unexpected dirt. If the writer environment is unavailable, report unavailable rather than leaving an implied active lease.

The preservation of the earlier failed heads and the exact fast-forward handoff are good discipline; this final bounded integration is the only remaining repository action before fresh review.