feat(addons): finalize event addon catalog and ai styling upgrade flow

app/Models/PackageAddon.php

@@ -41,4 +41,27 @@ class PackageAddon extends Model
             ],
         );
     }
+
+    public function resolvePaypalPrice(): ?float
+    {
+        $metadata = is_array($this->metadata) ? $this->metadata : [];
+        $price = $metadata['price_eur'] ?? null;
+
+        return is_numeric($price) ? (float) $price : null;
+    }
+
+    public function isSellableForProvider(?string $provider = null): bool
+    {
+        $provider = strtolower((string) ($provider ?? config('package-addons.provider') ?? config('checkout.default_provider', 'paypal')));
+
+        if (! $this->active) {
+            return false;
+        }
+
+        if ($provider === 'lemonsqueezy') {
+            return filled($this->variant_id);
+        }
+
+        return $this->resolvePaypalPrice() !== null;
+    }
 }