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

app/builder/page.tsx

@@ -175,7 +175,7 @@ export default function GunbuilderPage() {
           return updated;
         });
 
-        router.replace("/gunbuilder", { scroll: false });
+        router.replace("/builder", { scroll: false });
       }
     }
   }, [searchParams, router]);
@@ -223,7 +223,7 @@ export default function GunbuilderPage() {
       const payload = JSON.stringify(build);
       const encoded = window.btoa(payload);
       const origin = window.location?.origin ?? "";
-      const url = `${origin}/gunbuilder/build?build=${encodeURIComponent(
+      const url = `${origin}/builder/build?build=${encodeURIComponent(
         encoded,
       )}`;
       setShareUrl(url);
@@ -372,7 +372,7 @@ export default function GunbuilderPage() {
             {/* Primary actions now live under the total */}
             <div className="mt-2 flex flex-col items-stretch gap-2 sm:flex-row sm:flex-wrap">
               <Link
-                href="/gunbuilder/build"
+                href="/builder/build"
                 className={`w-full sm:w-auto rounded-md border border-amber-400/60 bg-amber-400/10 px-3 py-2 text-sm font-medium text-amber-200 hover:bg-amber-400/15 text-center transition-colors ${
                   selectedParts.length === 0
                     ? "opacity-40 cursor-not-allowed pointer-events-none"
@@ -598,7 +598,7 @@ export default function GunbuilderPage() {
                                     {selectedPart && selectedPart.url ? (
                                       <>
                                         <Link
-                                          href={`/gunbuilder/${category.id}`}
+                                          href={`/builder/${category.id}`}
                                           className="hidden md:inline-flex items-center justify-center rounded-md border border-zinc-700 bg-zinc-900/70 px-2 py-1 hover:bg-zinc-800 hover:border-zinc-600 transition-colors"
                                           aria-label="Change part"
                                           title="Change part"
@@ -618,7 +618,7 @@ export default function GunbuilderPage() {
                                       </>
                                     ) : hasParts ? (
                                       <Link
-                                        href={`/gunbuilder/${category.id}`}
+                                        href={`/builder/${category.id}`}
                                         className="inline-flex rounded-md border border-zinc-700 bg-zinc-900/70 px-2.5 py-1 text-[0.7rem] font-medium text-zinc-200 hover:bg-zinc-800 hover:border-zinc-600 transition-colors"
                                         onClick={() => {
                                           // If you want to pre-select something later, you can handle here.