[client/ui] Replace fyne UI with Wails (rename ui-wails to ui)

Removes the legacy fyne-based client/ui implementation and renames the
Wails replacement (client/ui-wails) to take its place at client/ui. Go
imports, frontend bindings, CI workflows, goreleaser configs and the
windows .syso icon path are updated to follow the rename.

client/ui/frontend/src/Layout.tsx

@@ -0,0 +1,45 @@
+import { NavLink, Outlet } from "react-router-dom";
+import { Activity, Bug, Network, Settings as SettingsIcon, Share2, Users } from "lucide-react";
+import { cn } from "./lib/cn";
+
+const nav = [
+  { to: "/", label: "Status", icon: Activity, end: true },
+  { to: "/peers", label: "Peers", icon: Share2 },
+  { to: "/networks", label: "Networks", icon: Network },
+  { to: "/profiles", label: "Profiles", icon: Users },
+  { to: "/settings", label: "Settings", icon: SettingsIcon },
+  { to: "/debug", label: "Debug", icon: Bug },
+];
+
+export default function Layout() {
+  return (
+    <div className="flex h-full">
+      <aside className="w-48 shrink-0 border-r border-nb-gray-200 bg-nb-gray-50 dark:border-nb-gray-800 dark:bg-nb-gray-940">
+        <div className="px-4 py-5 text-lg font-semibold text-netbird">NetBird</div>
+        <nav className="px-2">
+          {nav.map(({ to, label, icon: Icon, end }) => (
+            <NavLink
+              key={to}
+              to={to}
+              end={end}
+              className={({ isActive }) =>
+                cn(
+                  "flex items-center gap-2 rounded-md px-3 py-2 text-sm",
+                  isActive
+                    ? "bg-netbird/10 text-netbird"
+                    : "text-nb-gray-700 hover:bg-nb-gray-100 dark:text-nb-gray-300 dark:hover:bg-nb-gray-900",
+                )
+              }
+            >
+              <Icon className="h-4 w-4" strokeWidth={1.5} />
+              {label}
+            </NavLink>
+          ))}
+        </nav>
+      </aside>
+      <main className="flex-1 overflow-auto">
+        <Outlet />
+      </main>
+    </div>
+  );
+}