feat(ticket): implement DesfileEntryReservationController and related services for ticket reservations

app/Domains/Ticketing/Desfile/Services/DesfileEntryReservationPolicy.php

@@ -0,0 +1,31 @@
+<?php
+
+namespace App\Domains\Ticketing\Desfile\Services;
+
+use App\Domains\Ticketing\Ticket\Services\EntryReservationPolicy;
+use Illuminate\Validation\ValidationException;
+
+class DesfileEntryReservationPolicy implements EntryReservationPolicy
+{
+    public function validate(array $selections): void
+    {
+        $errors = [];
+        $seen = [];
+
+        foreach ($selections as $index => $selection) {
+            $variant = $selection['variant'];
+            if ($variant === null || $selection['inventory'] === null
+                || isset($seen[$variant->id])
+                || $variant->entryReservations()->lockForUpdate()->get()->isNotEmpty()) {
+                $errors["rows.{$index}.variant_id"] = 'La entrada ya no está disponible.';
+            }
+            if ($variant !== null) {
+                $seen[$variant->id] = true;
+            }
+        }
+
+        if ($errors !== []) {
+            throw ValidationException::withMessages($errors);
+        }
+    }
+}