refactor(metadata-protocol): carry the import-attached comments and doc-link imports the preamble move dropped

The move kept protocol.ts's imports by the identifiers its code uses, so
three comments attached to imports it dropped or moved went nowhere, and
seven import names that only the class's {@link} doc references use were
removed. Restored, each at its base place:

- the [#19295] block above `markErasedAuthoringInput`'s import, now in
  protocol-meta-type-schema.ts;
- the [#21207] inline note with `ephemeralStoredHashDigest` in the
  metadata-redaction import;
- the [#5488] note after the reference-sites import, where it stood;
- SDUI_MANIFEST_SERVICE, backfillOverlayBundleMembers,
  unboundItemDraftAddress, resolveItemLockLazily, REFERENCE_VALUE_TYPES,
  externalBindingDatasourceRefusal and ephemeralStoredHashDigest back in
  protocol.ts's import lists.

Comments and import lists only. The published index.d.ts is byte-identical
to the previous head's.

Claude-Session: https://claude.ai/code/session_01ADHkmR4MjTzeUv5x6tNkbk
Co-authored-by: Claude <noreply@anthropic.com>

Author: claude

packages/metadata-protocol/src/protocol-meta-type-schema.ts

@@ -12,6 +12,11 @@
 // `{ not: {} }` — is dropped from it. See the module header for the channels
 // that keep carrying the retirement's prescription.
 import { stripUnauthorableProperties } from './unauthorable-nodes.js';
+// [#19295] The output derivation of a `ZodPipe` erases the arm's own input
+// type, so an authoring arm that accepts a bare string is served as the
+// anonymous `{}`. This annotates that husk — and only that husk — so a
+// consumer can tell an ERASED authoring type from a member that genuinely
+// admits anything. See the module header for the predicate and its controls.
 import { markErasedAuthoringInput } from './erased-authoring-mark.js';
 import {
     applyAuditFieldGovernance,

packages/metadata-protocol/src/protocol.ts

@@ -16,13 +16,15 @@ import type { MetadataHostEngine } from './host-engine.js';
 import { omitInternalFieldsFromWriteResponse } from './write-response-internal-fields.js';
 import { staleSummaryRefusalOrThrow, withEarnedAnswer, type SummaryRecomputeRefusal } from '@objectstack/types';
 import {
+    SDUI_MANIFEST_SERVICE,
     stampHtmlPageRequires,
     type RuntimePendingDeclarations,
 } from './runtime-authoring-gate.js';
 import type { RuntimeAuthoringIssue } from './runtime-authoring-gate.js';
 // [#6418] `sys_metadata`'s overlay-uniqueness indexes: probe-first DDL plus the
 // ADR-0120 D4 reporting that replaced this file's empty `catch` blocks.
 import {
+    backfillOverlayBundleMembers,
     overlayMemberWhere,
 } from './migrations/overlay-index.js';
 import {
@@ -33,12 +35,14 @@ import {
     packageScopedRowWhere,
     packagelessAddressAmbiguityRefusal,
     resetEnvWritableMetadataTypes,
+    unboundItemDraftAddress,
     versionNotFoundError,
     type SysMetadataEngine,
 } from './sys-metadata-repository.js';
 import { managedItemSealedSentence, packagedBaseRegimeRow, packagedBaseRegimeSentence } from './packaged-base-regime.js';
 import {
     resolveItemLock,
+    resolveItemLockLazily,
     resolveOverlayLockLayer,
     storedRowDocument,
     withItemLockFamily,
@@ -115,13 +119,15 @@ import { authoringClientOf, storedDraftChanges } from './draft-changes.js';
 import {
     parseFilterAST,
     isFilterAST,
+    REFERENCE_VALUE_TYPES,
     foldQueryAliasSlots,
     QUERY_TRANSPORT_ALIAS_SLOTS,
     QUERY_TRANSPORT_DOLLAR_ALIASES,
     QUERY_TRANSPORT_DOLLAR_PARAMS,
     type DroppedFieldsEvent,
     type EngineQueryOptionsParsed,
     type ValidationAdvisoryEvent,
+    externalBindingDatasourceRefusal,
 } from '@objectstack/spec/data';
 import { PLURAL_TO_SINGULAR, SINGULAR_TO_PLURAL, unrecognisedMetaTypeRefusal } from '@objectstack/spec/shared';
 // [#13331] The cluster fan-out transport type only — the protocol never
@@ -180,6 +186,15 @@ import {
 import { ManifestSchema, manifestIdRefusal } from '@objectstack/spec/kernel';
 import { stripReadDecorations } from '@objectstack/spec/kernel';
 import { REFERENCE_SITES } from './reference-sites.js';
+// [#5488] The `@objectstack/spec/api` import that stood here — `ApiEndpointSchema`,
+// `validateApiEndpointDeclarations`, `type ApiEndpoint` — went with
+// `gateApiDraftsForPublish` (see its retirement note in `publishPackageDrafts`).
+// This module no longer judges endpoints at all: `api` is code-only since #5488,
+// so no `api` draft can be authored here, and the ONE judge of what is servable
+// stays `validateApiEndpointDeclarations` on the artifact route (stack schema,
+// `publishPackage` #5189, and `buildEndpointIndex` at load, PR #5203). An
+// endpoint-shaped import left behind with no caller reads as a capability this
+// module still has (#3950), so it is removed rather than parked.
 import {
     computeMetadataDiagnostics,
     computeViewReferenceDiagnostics,
@@ -204,6 +219,9 @@ import {
     storedMetadataBodyGroupingRefusal,
     storedMetadataBodyPredicateRefusal,
     storedMetadataBodyProjection,
+    // [#21207] The stored content hash of the same rows: served keyed, never
+    // evaluated — see `STORED_METADATA_HASH_COLUMNS`.
+    ephemeralStoredHashDigest,
     servedContentHash,
     serveStoredHashTokens,
     serveStoredMetadataHashColumnRows,