feat(dashboard): kategori sayfalarında ana alanı tam genişlik yap

Araç ve katalog model detay sayfalarındaki max-w-4xl cap'i kaldırıldı;
kategori grid'i geniş monitörde xl:4 / 2xl:5 sütuna çıkıyor. Geniş
ekranlarda yanlardaki boşluk dolduruluyor ve kategori isimleri artık
kısaltılmadan sığıyor.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/web/src/routes/dashboard/catalog_/$brandName_/$modelId/index.tsx

@@ -121,7 +121,7 @@ function CatalogVehiclePage() {
 
   if (vehicleLoading) {
     return (
-      <div className="mx-auto max-w-4xl space-y-6">
+      <div className="space-y-6">
         <Skeleton className="h-8 w-64" />
         <Skeleton className="h-64 w-full" />
       </div>
@@ -129,7 +129,7 @@ function CatalogVehiclePage() {
   }
 
   return (
-    <div className="mx-auto max-w-4xl space-y-6">
+    <div className="space-y-6">
       {/* Header / Breadcrumb */}
       <div className="flex items-center justify-between">
         <div className="flex items-center gap-3">

apps/web/src/routes/dashboard/vehicles_/$id/categories_/$categoryId.tsx

@@ -36,7 +36,7 @@ function SchemaViewerFallback() {
 
 function CategoryGridFallback() {
   return (
-    <div className="grid gap-3 sm:grid-cols-2 lg:grid-cols-3">
+    <div className="grid gap-3 sm:grid-cols-2 lg:grid-cols-3 xl:grid-cols-4 2xl:grid-cols-5">
       {KEYS_6.map((__k) => (
         <Skeleton key={__k} className="h-24 w-full rounded-lg" />
       ))}

apps/web/src/routes/dashboard/vehicles_/$id/index.tsx

@@ -43,7 +43,7 @@ function VehicleDetailPage() {
 
   if (vehicleLoading) {
     return (
-      <div className="mx-auto max-w-4xl space-y-6">
+      <div className="space-y-6">
         {/* Header skeleton: back button + logo + 2-line title */}
         <div className="flex items-center gap-3">
           <Skeleton className="h-9 w-9 rounded-md" />
@@ -79,7 +79,7 @@ function VehicleDetailPage() {
   }
 
   return (
-    <div className="mx-auto max-w-4xl space-y-6">
+    <div className="space-y-6">
       {/* Header */}
       <div className="flex items-center gap-3">
         <Button