feat(dashboard): live notifications phase 1 — presence, live unread, in-app toasts

Shared RealtimeProvider opens ONE dashboard-wide IIOS message socket reused by
the messenger tab and the new NotificationCenter. CrmMessagingAdapter gains
setFocus (drives presence/push suppression) and subscribeActivity (joins all
of the caller's threads, fans out incoming messages). NotificationCenter shows
a clickable toast on new messages when you're not on the messenger tab and
deep-links to the conversation. Pulls @insignia/iios-messaging-ui@0.1.7.

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

src/lib/realtime.tsx

@@ -0,0 +1,43 @@
+"use client";
+
+// One shared IIOS message socket for the whole dashboard, so the messenger tab AND the app-wide
+// notification center use a single connection (not one each). Opened at the dashboard level and
+// kept alive across tab switches; the messenger tab reuses it via useRealtime().
+
+import { createContext, useContext, useEffect, useState, type ReactNode } from "react";
+import { useQuery } from "@abe-kap/appshell-sdk/react";
+import { MessageSocket } from "@insignia/iios-kernel-client";
+import { isShellConfigured } from "./appshell";
+
+const RealtimeContext = createContext<MessageSocket | null>(null);
+interface RealtimeDTO { url: string; audience: string; token?: string }
+const SHELL = isShellConfigured();
+
+function LiveRealtimeProvider({ children }: { children: ReactNode }) {
+  const rt = useQuery<RealtimeDTO>("crm.messenger.realtime", {});
+  const [socket, setSocket] = useState<MessageSocket | null>(null);
+  const url = rt.data?.url;
+  const token = rt.data?.token;
+  useEffect(() => {
+    if (!url || !token) return;
+    const s = new MessageSocket({ serviceUrl: url, token, autoConnect: false });
+    s.connect();
+    setSocket(s);
+    return () => {
+      s.disconnect();
+      setSocket(null);
+    };
+  }, [url, token]);
+  return <RealtimeContext.Provider value={socket}>{children}</RealtimeContext.Provider>;
+}
+
+export function RealtimeProvider({ children }: { children: ReactNode }) {
+  // SHELL is a build-time constant, so the same branch runs every render (Rules-of-Hooks safe).
+  if (!SHELL) return <>{children}</>;
+  return <LiveRealtimeProvider>{children}</LiveRealtimeProvider>;
+}
+
+/** The shared socket, or null (demo mode / not yet connected). */
+export function useRealtime(): MessageSocket | null {
+  return useContext(RealtimeContext);
+}