Fix R15: Shelly prefix from mDNS instance, discovery broadcast once, targeted confirm

- AssignDevice derives the Shelly MQTT prefix from the mDNS service instance name
  (the device id) instead of the slugified topic identifier (which carries the
  _shelly._tcp suffix); non-Shelly devices get no prefix.
- IngestDiscoveryMessage broadcasts DeviceDiscovered only on first creation, not on
  every retained/periodic re-publish.
- The generic Confirm modal can target its event at the opening component (->to),
  so a shared event name can't be caught by an unrelated component.

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

app/Jobs/IngestDiscoveryMessage.php

@@ -46,7 +46,9 @@ class IngestDiscoveryMessage implements ShouldQueue
             ],
         );
 
-        if (($existing?->status ?? 'new') === 'new') {
+        // Announce only on FIRST discovery — the sidecar re-publishes retained/periodic
+        // messages, so broadcasting on every message would spam the "Neue Geräte" panel.
+        if ($existing === null) {
             DeviceDiscovered::dispatch($finding->uuid);
         }
     }

app/Livewire/Modals/AssignDevice.php

@@ -42,13 +42,18 @@ class AssignDevice extends ModalComponent
         ]);
 
         $finding = $this->finding();
+        $isShelly = $finding->vendor === 'Shelly';
+
+        // The Shelly MQTT topic prefix is its device id — the mDNS service INSTANCE name
+        // (finding->name), not the slugified topic identifier which carries the _shelly._tcp suffix.
+        $prefix = $isShelly ? ($finding->name ?: $finding->identifier) : null;
 
         $device = Device::create([
             'name' => $this->name,
             'vendor' => $finding->vendor,
             'model' => $finding->model,
-            'protocol' => $finding->vendor === 'Shelly' ? 'mqtt' : null,
+            'protocol' => $isShelly ? 'mqtt' : null,
-            'config' => ['mqtt_prefix' => $finding->identifier],
+            'config' => $prefix ? ['mqtt_prefix' => $prefix] : null,
             'room_id' => $this->roomId ?: null,
             'status' => 'active',
         ]);

app/Livewire/Modals/Confirm.php

@@ -17,6 +17,7 @@ class Confirm extends ModalComponent
     public string $body = '';
     public string $confirmLabel = '';
     public string $event = '';
+    public string $to = '';
     public bool $danger = false;
 
     public static function modalMaxWidth(): string
@@ -24,18 +25,23 @@ class Confirm extends ModalComponent
         return 'md';
     }
 
-    public function mount(string $title, string $body, string $confirmLabel, string $event, bool $danger = false): void
+    public function mount(string $title, string $body, string $confirmLabel, string $event, string $to = '', bool $danger = false): void
     {
         $this->title = $title;
         $this->body = $body;
         $this->confirmLabel = $confirmLabel;
         $this->event = $event;
+        $this->to = $to;
         $this->danger = $danger;
     }
 
     public function confirm(): void
     {
-        $this->dispatch($this->event);
+        // Target the opener (if given) so an event name can't collide with another component.
+        $this->to !== ''
+            ? $this->dispatch($this->event)->to($this->to)
+            : $this->dispatch($this->event);
+
         $this->closeModal();
     }
 

resources/views/livewire/devices/show.blade.php

@@ -93,7 +93,7 @@
                 <x-panel :title="__('devices.actions')">
                     <div class="flex flex-col gap-2">
                         <button type="button"
-                                wire:click="$dispatch('openModal', { component: 'modals.confirm', arguments: { title: @js(__('devices.restart_confirm_title')), body: @js(__('devices.restart_confirm_body', ['name' => $device->name])), confirmLabel: @js(__('devices.restart')), event: 'restartDevice', danger: true } })"
+                                wire:click="$dispatch('openModal', { component: 'modals.confirm', arguments: { title: @js(__('devices.restart_confirm_title')), body: @js(__('devices.restart_confirm_body', ['name' => $device->name])), confirmLabel: @js(__('devices.restart')), event: 'restartDevice', to: 'devices.show', danger: true } })"
                                 class="flex items-center gap-2.5 rounded-lg border border-line-soft bg-raised px-3 py-2.5 text-[13px] font-semibold text-ink hover:border-line transition-colors">
                             <x-icon name="activity" :size="16" class="text-ink-2" /> {{ __('devices.restart') }}
                         </button>