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>

src/components/dashboard/dashboard.tsx

@@ -15,6 +15,8 @@ import { Support } from "./support";
 import { Rules } from "./rules";
 import { AiAssistant } from "./ai-assistant";
 import { TeamManagement } from "./team-management";
+import { Messenger } from "./messenger";
+import { Inbox } from "./inbox";
 import "../../app/dashboard/dashboard.css";
 
 export function Dashboard() {
@@ -45,6 +47,8 @@ export function Dashboard() {
               : active === "support" ? <Support />
               : active === "rules" ? <Rules />
               : active === "ai" ? <AiAssistant />
+              : active === "messenger" ? <Messenger />
+              : active === "inbox" ? <Inbox />
               : active === "team" ? <TeamManagement />
               : <ComingSoon title={title} icon={item?.icon ?? "dashboard"} onGo={setActive} />}
           </ToastProvider>