Phase 890: registry split + delivery receipt responder helper (v0.8.857)

Non-breaking refactor — split gossip-rpc-registry into entries/lookup/validate
modules; buildGuildRpcTargetedDeliveryReceiptResponse() shared by audit/digest
responders; platform-search-rpc-pull-mixin for search mesh config pulls. test:ci-phase890
passes (46/50, cutover deferred).

mixins/runtime/features/platform-audit-archive-rpc-responders-mixin.js

@@ -1,20 +1,19 @@
 'use strict'
 
 const {
-  assertGuildRpcTargetResponder,
-  buildGuildRpcDeliveryResponseEnvelope,
+  buildGuildRpcTargetedDeliveryReceiptResponse,
   markRpcResponse
 } = require('../../../gossip-rpc-pull')
 
 /** Audit export archive protomux-rpc responders (Phase 885 extract). */
 const platformAuditArchiveRpcRespondersMixin = {
   async _buildAuditExportArchiveResponsePayload (payload) {
-    if (!payload?.archiveId) return null
-    if (!assertGuildRpcTargetResponder(payload, this)) return null
-    await this._initDeliveryReceipts(payload.guildId)
-    const row = await this.deliveryReceipts.getAuditExportArchive(payload.archiveId)
-    if (!row?.entries?.length) return null
-    return buildGuildRpcDeliveryResponseEnvelope(row, this, payload)
+    return buildGuildRpcTargetedDeliveryReceiptResponse(this, payload, {
+      resourceIdKey: 'archiveId',
+      fetchRow: (platform, p) =>
+        platform.deliveryReceipts.getAuditExportArchive(p.archiveId),
+      validateRow: (row) => Boolean(row?.entries?.length)
+    })
   },
 
   async _handleAuditExportArchiveRequestRpc (payload) {

mixins/runtime/features/platform-automation-digest-snapshot-rpc-responders-mixin.js

@@ -1,20 +1,19 @@
 'use strict'
 
 const {
-  assertGuildRpcTargetResponder,
-  buildGuildRpcDeliveryResponseEnvelope,
+  buildGuildRpcTargetedDeliveryReceiptResponse,
   markRpcResponse
 } = require('../../../gossip-rpc-pull')
 
 /** Automation digest snapshot protomux-rpc responders (Phase 885 extract). */
 const platformAutomationDigestSnapshotRpcRespondersMixin = {
   async _buildAutomationDigestExportSnapshotResponsePayload (payload) {
-    if (!payload?.snapshotId) return null
-    if (!assertGuildRpcTargetResponder(payload, this)) return null
-    await this._initDeliveryReceipts(payload.guildId)
-    const row = await this.deliveryReceipts.getAutomationDigestExportSnapshot(payload.snapshotId)
-    if (!row?.body?.length) return null
-    return buildGuildRpcDeliveryResponseEnvelope(row, this, payload)
+    return buildGuildRpcTargetedDeliveryReceiptResponse(this, payload, {
+      resourceIdKey: 'snapshotId',
+      fetchRow: (platform, p) =>
+        platform.deliveryReceipts.getAutomationDigestExportSnapshot(p.snapshotId),
+      validateRow: (row) => Boolean(row?.body?.length)
+    })
   },
 
   async _handleAutomationDigestExportSnapshotRequestRpc (payload) {