fixed the name change from gunbuilder to builder and added the TM for trademark

app/builder/[categoryId]/[partId]/page.tsx

@@ -131,10 +131,10 @@ export default function PartDetailPage() {
         <div className="mx-auto max-w-6xl px-4 py-6 lg:py-10">
           <h1 className="text-2xl font-semibold mb-4">Category Not Found</h1>
           <Link
-            href="/gunbuilder"
+            href="/builder"
             className="text-amber-300 hover:text-amber-200 underline"
           >
-            Return to Gunbuilder
+            Return to Builder
           </Link>
         </div>
       </main>
@@ -147,14 +147,14 @@ export default function PartDetailPage() {
         {/* Breadcrumbs */}
         <nav className="mb-4 text-xs text-zinc-500">
           <Link
-            href="/gunbuilder"
+            href="/builder"
             className="hover:text-zinc-300 transition-colors"
           >
-            Gunbuilder
+            Builder
           </Link>
           <span className="mx-1">/</span>
           <Link
-            href={`/gunbuilder/${categoryId}`}
+            href={`/builder/${categoryId}`}
             className="hover:text-zinc-300 transition-colors"
           >
             {category.name}
@@ -176,7 +176,7 @@ export default function PartDetailPage() {
               {error ?? "We couldn’t find this product."}
             </p>
             <Link
-              href={`/gunbuilder/${categoryId}`}
+              href={`/builder/${categoryId}`}
               className="text-amber-300 hover:text-amber-200 underline text-sm"
             >
               Back to {category.name} parts
@@ -352,7 +352,7 @@ export default function PartDetailPage() {
 
                 <div className="space-y-2">
                   <Link
-                    href={`/gunbuilder?select=${categoryId}:${product.id}`}
+                    href={`/builder?select=${categoryId}:${product.id}`}
                     className="block w-full rounded-md bg-amber-400 text-black text-sm font-semibold text-center py-2.5 hover:bg-amber-300 transition-colors"
                   >
                     Add to Build