feat(messenger): wire the channel-roster import adapter seam

Phase D of channel-roster import. CrmMessagingAdapter.addMembers() proxies the
new crm.messenger.participant.addMany door action, enabling the SDK's '#' import
affordance in the channel/group settings panel. Pulls @insignia/iios-messaging-ui@0.1.8.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/lib/crm-messaging-adapter.ts

@@ -7,6 +7,7 @@
 
 import type {
   Attachment,
+  BulkAddResult,
   ChannelSummary,
   ChannelVisibility,
   Conversation,
@@ -247,6 +248,12 @@ export class CrmMessagingAdapter implements MessagingAdapter {
     await this.sdk.command("crm.messenger.participant.add", { threadId, userId });
   }
 
+  /** Bulk import (e.g. everyone from another channel). IIOS governs both ends: you must belong to
+   *  the source channel to read its roster, and OPA re-checks who may add to this thread. */
+  async addMembers(threadId: string, userIds: string[]): Promise<BulkAddResult> {
+    return this.sdk.command<BulkAddResult>("crm.messenger.participant.addMany", { threadId, userIds });
+  }
+
   async removeMember(threadId: string, userId: string): Promise<void> {
     await this.sdk.command("crm.messenger.participant.remove", { threadId, userId });
   }