feat(dashboard): GuruConnect v2 operator console (pass 1)

React + Vite + TypeScript SPA: scaffold, operations-terminal design
system, Bearer-token auth, and the Machines view.

- Design system: OKLCH-tinted dark theme (ink-slate + signal-cyan),
  Hanken Grotesk + JetBrains Mono, status-color language
  (online/offline/granted/pending/denied/not_required), motion with
  prefers-reduced-motion honored.
- Auth: token in sessionStorage via ref (never React state), protected
  routes, 401 session teardown, admin-gated per-agent-key UI.
- Machines view: data table (sticky header, keyboard-activated rows,
  skeleton loading, actionable empty/error states), non-blocking detail
  drawer, delete confirm, admin key management with copy-once reveal.
- UI primitives: Modal (focus trap + inert + portal + dialogStack),
  Drawer, Table, Badge/StatusDot, toast, states.
- Typed API client normalizing the two error-envelope shapes.

Passed Code Review (no blockers), impeccable critique-and-polish, and
local gates (tsc/lint/build green). Dev-only Vite proxy to :3002.

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

dashboard/src/components/layout/Topbar.tsx

@@ -0,0 +1,51 @@
+import { useAuth } from "../../auth/AuthContext";
+import { useRelayStatus } from "../../lib/useRelayStatus";
+import { Badge } from "../ui/Badge";
+import { Button } from "../ui/Button";
+import { LogoutIcon } from "./icons";
+
+function roleTone(role: string | undefined): "accent" | "ok" | "neutral" {
+  if (role === "admin") return "accent";
+  if (role === "operator") return "ok";
+  return "neutral";
+}
+
+export function Topbar() {
+  const { user, logout } = useAuth();
+  const { live, checking } = useRelayStatus();
+
+  const relayClass = live ? "relay relay--live" : "relay relay--down";
+  const relayLabel = checking ? "probing" : live ? "live" : "offline";
+
+  return (
+    <header className="topbar">
+      <div
+        className={relayClass}
+        title="GuruConnect relay connection"
+        aria-label={`Relay ${relayLabel}`}
+      >
+        <span className="relay__pip" aria-hidden="true" />
+        <span>Relay</span>
+        <span className="relay__label mono">{relayLabel}</span>
+      </div>
+
+      <div className="topbar__spacer" />
+
+      <div className="topbar__user">
+        <div className="topbar__id">
+          <span className="topbar__username">{user?.username}</span>
+        </div>
+        <Badge tone={roleTone(user?.role)}>{user?.role ?? "—"}</Badge>
+        <Button
+          variant="ghost"
+          size="sm"
+          onClick={() => void logout()}
+          aria-label="Log out"
+        >
+          <LogoutIcon width={15} height={15} />
+          Logout
+        </Button>
+      </div>
+    </header>
+  );
+}