feat(dashboard): real user in sidebar + sign-out; strip demo/mock hints

- Sidebar footer now shows the ACE identity (was static 'James Carter') with a
  Sign-out menu; topbar user gets a Sign-out dropdown too. Both call useAuth().logout.
- Remove all visible 'Demo:' hints from login + register and the 'Demo mode' subtitle.

src/components/dashboard/sidebar.tsx

@@ -1,9 +1,16 @@
 "use client";
 
-import { ChevronsUpDown } from "lucide-react";
+import { useState } from "react";
+import { useRouter } from "next/navigation";
+import { ChevronsUpDown, LogOut } from "lucide-react";
+import { useAuth } from "@abe-kap/appshell-sdk/react";
 import { Icon } from "./ui";
 import { user } from "./account-data";
 
+function initialsOf(name: string): string {
+  return name.split(/\s+/).filter(Boolean).slice(0, 2).map((p) => p[0]).join("").toUpperCase() || "?";
+}
+
 export type NavItem = { key: string; label: string; icon: string; subtitle?: string };
 export type NavGroup = { title: string; items: NavItem[] };
 
@@ -61,6 +68,21 @@ export const NAV_GROUPS: NavGroup[] = [
 export const NAV_ITEMS: NavItem[] = NAV_GROUPS.flatMap((g) => g.items);
 
 export function Sidebar({ active, onSelect }: { active: string; onSelect: (k: string) => void }) {
+  const router = useRouter();
+  const { user: me, logout } = useAuth();
+  const [menuOpen, setMenuOpen] = useState(false);
+  // Real signed-in identity from the App Context Envelope; fall back to the static
+  // demo user only when the Shell isn't wired.
+  const name = me?.displayName || user.name;
+  const initials = me ? initialsOf(me.displayName) : user.initials;
+  const secondary = me?.email || user.role;
+
+  async function signOut() {
+    setMenuOpen(false);
+    try { await logout(); } catch { /* ignore — proceed to portal either way */ }
+    router.replace("/portal/login");
+  }
+
   return (
     <aside className="dash-sidebar">
       <div className="dash-brand">
@@ -82,12 +104,20 @@ export function Sidebar({ active, onSelect }: { active: string; onSelect: (k: st
         ))}
       </nav>
 
-      <div className="sb-foot">
-        <button className="sb-user">
-          <span className="av" style={{ background: user.avatarGradient, display: "grid", placeItems: "center", color: "#fff", fontWeight: 700, fontSize: 12 }}>{user.initials}</span>
-          <div style={{ flex: 1, textAlign: "left" }}>
-            <div className="nm">{user.name}</div>
-            <div className="rl">{user.role}</div>
+      <div className="sb-foot" style={{ position: "relative" }}>
+        {menuOpen && (
+          <>
+            <div className="tm-menu-scrim" onClick={() => setMenuOpen(false)} />
+            <div className="sb-user-menu" role="menu">
+              <button className="danger" onClick={signOut}><LogOut size={15} /> Sign out</button>
+            </div>
+          </>
+        )}
+        <button className="sb-user" onClick={() => setMenuOpen((o) => !o)} aria-haspopup="menu" aria-expanded={menuOpen}>
+          <span className="av" style={{ background: user.avatarGradient, display: "grid", placeItems: "center", color: "#fff", fontWeight: 700, fontSize: 12 }}>{initials}</span>
+          <div style={{ flex: 1, textAlign: "left", minWidth: 0 }}>
+            <div className="nm">{name}</div>
+            <div className="rl" style={{ overflow: "hidden", textOverflow: "ellipsis" }}>{secondary}</div>
           </div>
           <ChevronsUpDown size={15} />
         </button>