feat: Messenger + Inbox on the AppShell data door + live IIOS socket

New "Communication" area in the dashboard, built on the existing appshell-sdk wiring
(useQuery/sdk.command) like Team, with the IIOS MessageSocket for live streaming.

- messenger-api.ts / inbox-api.ts: mock (demo) + live (crm.messenger.* / crm.inbox.*)
  behind one interface, switched by isShellConfigured().
- messenger-socket.tsx: MessengerSocketProvider — one IIOS MessageSocket per panel
  (openThread history + live on("message") + send). REST 4s poll is the automatic
  fallback when the socket isn't connected.
- messenger.tsx: conversation list ⇄ thread + composer + new-chat people picker
  (DM 1 person / group 2+); inbox.tsx: filterable feed with Done/Snooze/Archive.
- sidebar: Communication group (Messenger + Inbox, always-visible); dashboard: panel switch.
- .npmrc: add the @insignia Gitea registry for @insignia/iios-kernel-client.

Works on mock immediately; goes live once NEXT_PUBLIC_SUPABASE_URL + the BFF + be-crm are set.
tsc clean; next build passes.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

package.json

@@ -10,6 +10,7 @@
   },
   "dependencies": {
     "@abe-kap/appshell-sdk": "^0.2.6",
+    "@insignia/iios-kernel-client": "^0.1.4",
     "clsx": "^2.1.1",
     "lucide-react": "^1.21.0",
     "next": "16.2.9",