fix: Correct button visibility logic

- Mitarbeiter: sees buttons only for OWN pending assignment
- Chef/Disponent: sees buttons for ALL assignments

src/views/OrderDetailView.vue

@@ -258,8 +258,8 @@ const spotsRemaining = computed(() => {
               {{ getStatusLabel(assignment.status) }}
             </span>
             
-            <!-- Confirm/Decline buttons - for assigned user OR management -->
-            <template v-if="assignment.status === 'pending' || authStore.canManageOrders">
+            <!-- Confirm/Decline buttons - for assigned user (own assignment) OR management (any) -->
+            <template v-if="(assignment.user_id === authStore.user?.id && assignment.status === 'pending') || authStore.canManageOrders">
               <button 
                 class="btn btn-success text-sm" 
                 :class="{ 'opacity-50': assignment.status === 'confirmed' }"