feat(messenger): channels + @mentions in the CRM SDK adapter

CrmMessagingAdapter now implements the full SDK contract:
- browseChannels/createChannel/leaveChannel over the be-crm channel door
  (crm.messenger.channel.*); joinChannel is a governed public self-join over
  the socket (openThread) — the BFF has no join verb, OPA enforces it
- listMembers over crm.messenger.members → drives @mention autocomplete
- send forwards mentions[] on the socket path (→ IIOS MENTION inbox items)

So the CRM messenger (rendered by the SDK) now gets sectioned Channels/DMs,
browse+join+create, and @mention autocomplete/highlight — no embedded code.
(SDK re-packed to the local tarball; publish for deploy.) tsc + next build green.

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

package-lock.json

@@ -1030,7 +1030,7 @@
     "node_modules/@insignia/iios-messaging-ui": {
       "version": "0.1.0",
       "resolved": "file:../iios/packages/iios-messaging-ui/insignia-iios-messaging-ui-0.1.0.tgz",
-      "integrity": "sha512-6pSVWACjex1sXWzVqx+42rM6vgWEJ+1ud5y3DLKogJiQmfgFZgCB8vTw0PN/5FECugXC7iGuc9rV9RsHsP+EDw==",
+      "integrity": "sha512-B6Vzb75lBv4W3ZuKE4muMSz/OyUrE0NxImUI6sHaCBby5xveHVyanPiwkxiaqg9zZPYQMYiZRMONYwlNqyJvig==",
       "peerDependencies": {
         "@insignia/iios-kernel-client": "*",
         "react": ">=18"