The issue's "0 conditional branches" premise missed a live one: the `!isZcode`
shared-hooks exclusion (bin/install.js). Fold it onto descriptor-driven
hostBehaviors.skipSharedHooksInstall:true (zcode's golden has zero hook files —
byte-parity verified) and drop the now-unused isZcode destructure. Zero live
runtime==='zcode'/isZcode branches remain (AC2 source-grep guard over
bin/install.js + install-engine.cts + surface.cts + runtime-artifact-conversion.cts).
The 6 CLI-bookkeeping zcode mentions (--zcode flag, menu, roster, help) stay.
Reference test (declarative-reference-zcode.test.cjs): profileOf → declarative-cli;
createDeclarativeAdapter({runtime:'zcode'}).kind → declarative; a real install emits
the invocable nested-skills/commands/agents surface (no hooks); negotiateHostCapabilities
fail-closes (empty/corrupt descriptor; the nested/maxDepth undocumented sub-axes degrade
to most-restrictive); validateCapability clean.
UPGRADES documented as BLOCKED (verified doc gaps — NOT guessed, to avoid a
non-functional false-green): both of ZCode's documented capabilities lack a published
on-disk config format.
- Hook automation: zcode.z.ai/en/docs/plugin documents the Hook component only as
"automation hooks triggered on specific events" (capability detected from directory
layout) — no config file format/location/event schema. Cannot faithfully wire.
- MCP registration: zcode.z.ai/en/docs/mcp-services says servers are "stored in the
.zcode configuration file" (UI-only) with no documented on-disk filename/path/schema —
exactly the settings-filename gap the issue AC anticipated.
Both are documented (with the search trail) in the capability matrix + how-to, per AC4's
block-documentation clause; hookBus/transport stay declared for when ZCode publishes the
formats. No hook scripts or MCP artifacts added → no golden change, no other-runtime impact.
Golden: byte-identical for all 16 runtimes (the fold is byte-parity; no upgrade artifacts).
Matrix ## zcode EoS note + how-to; changeset (Changed). capability-registry regenerated.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
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