fix(spec): the engine contract header names both optional members, and the consumer changeset declares Metadata-protocol none

The contract review on 7237921 asked for two should-fixes. The
IObjectQLEngine header now names getDisabledActions beside judgeFilter
as optional by ruling. The four consumer packages add no authorable key
of their own, so their patch changeset declares Metadata-protocol: none;
the key stays declared `added` on spec's minor changeset.

Co-Authored-By: Claude <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017ihL2fi9zfJhUTubyJYb6V

Author: claude

.changeset/27842-disabled-actions-served.md

@@ -8,7 +8,7 @@
 fix: `GET /meta/object` serves which packaged actions are switched off beside the item, and a switched-off action is refused with a plain sentence
 
 Clause-②: yes (widening)
-Metadata-protocol: added
+Metadata-protocol: none
 
 - **Served beside the object** (`@objectstack/metadata-protocol`, `@objectstack/rest`). `GET /api/v1/meta/object/:name` serves `disabledActions` beside `item`: the names in `item.actions` that the deployment's activation ledger switches off. `GET /api/v1/meta/object` serves the same answer keyed by object name. The default cached door carries it too, read live on every call and kept out of the ETag, so a read that carries it is answered in full rather than `304 Not Modified`. The key is absent where no ledger answered (no engine, or an engine with no ledger attached), on a draft read, and on every type other than `object`. `item.actions` is unchanged. The protocol reads the engine's `getDisabledActions` through the kernel's service table by name and imports no engine.
 - **The fact it serves** (`@objectstack/objectql`). `ObjectQL.getDisabledActions()` returns the names the engine's activation projection switches off, the same projection both dispatch doors consult before they refuse a call, or `undefined` when no ledger is attached. `listDisabledActions()` is unchanged.

packages/spec/src/contracts/objectql-engine.ts

@@ -230,9 +230,10 @@ export type EngineFilterJudgement =
  * guarded call into a `possibly undefined` error and push code back toward the
  * `any` this contract exists to remove.
  *
- * One member is optional by ruling, not by this default: {@link judgeFilter}
- * (#19995 ruling C). Its callers must work with an engine that lacks it, so the
- * optional mark states that requirement in the type.
+ * Two members are optional by ruling, not by this default: {@link judgeFilter}
+ * (#19995 ruling C) and {@link getDisabledActions} (#27842 ruling letter B,
+ * the `getFlowRegistration?` shape). Their callers must work with an engine
+ * that lacks them, so the optional mark states that requirement in the type.
  */
 export interface IObjectQLEngine extends IDataEngine {
     // ── Schema access ────────────────────────────────────────────────────