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/sidebar.tsx

@@ -29,6 +29,13 @@ export const NAV_GROUPS: NavGroup[] = [
       { key: "pipeline", label: "Pipeline", icon: "pipeline" },
     ],
   },
+  {
+    title: "Communication",
+    items: [
+      { key: "messenger", label: "Messenger", icon: "send", subtitle: "Chat with your team and clients" },
+      { key: "inbox", label: "Inbox", icon: "bell", subtitle: "Mentions, replies and updates for you" },
+    ],
+  },
   {
     title: "Workspace",
     items: [
@@ -72,7 +79,7 @@ export const NAV_ITEMS: NavItem[] = NAV_GROUPS.flatMap((g) => g.items);
 // brand-new user with no membership); every other item requires membership, and the
 // items mapped here additionally require the given permission. Unmapped items are
 // shown to any member. This is UX only — be-crm still enforces every action.
-const ALWAYS_VISIBLE = new Set(["dashboard", "profile"]);
+const ALWAYS_VISIBLE = new Set(["dashboard", "profile", "messenger", "inbox"]);
 const NAV_PERMISSION: Record<string, string | undefined> = {
   team: "team.manage",
   people: "team.manage",