Guest Wi-Fi dashboard card (network + rotating password + join QR)

New home card 'unifi.guest_wifi': shows the guest SSID, the current
rotated password (unifi.password_rotation.last_password), and a WPA
join QR built from the WIFI: string. Polls app/unifi/guest-card/data
(auth) every 60s so it updates the moment the rotation engine changes
the password — the QR regenerates client-side to match. Self-hides
until enabled with an SSID and a rotated password; grant-gated via
Admin -> Settings -> Dashboard Cards. New settings (WiFi rotation
section): enable + network name + card title.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/UnifiServiceProvider.php

@@ -24,6 +24,22 @@ class UnifiServiceProvider extends ServiceProvider
         $this->loadRoutesFrom(__DIR__ . '/routes/unifi.php');
         $this->loadMigrationsFrom(__DIR__ . '/../database/migrations');
 
+        // "/" home card: guest Wi-Fi network + current rotating password +
+        // QR (re-renders when the password changes). Grant-gated via
+        // Admin → Settings → Dashboard Cards; self-hides until enabled and
+        // a password has been rotated.
+        try {
+            app(\App\Support\DashboardCardRegistry::class)->register(
+                'unifi.guest_wifi',
+                'Guest Wi-Fi',
+                'UnifiGuestWifi',
+                fn (\App\Models\User $user) => \Dashboard\Unifi\Http\Controllers\GuestCardController::resolve($user),
+                'The guest network name, current password, and a join QR code — updates automatically when the password rotates.',
+            );
+        } catch (\Throwable) {
+            // Older shell without the card registry — skip.
+        }
+
         // Tell the shell's nav sidebar which unifi nav items the user
         // can see: pages whose required_permission the user holds through
         // groups, plus pages granted via the Settings → Access tab. The