feat(i18n): improve ai chat and settings localization

app/api/create-client-user/route.ts

@@ -13,7 +13,7 @@ export async function POST(request: Request) {
   const actor = await getSessionContextFromHeaders(new Headers(request.headers));
 
   if (!actor) {
-    return NextResponse.json({ error: "Müşteri daveti için giriş yapmalısınız." }, { status: 401 });
+    return NextResponse.json({ error: "clients.detail.portalInviteUnauthenticated" }, { status: 401 });
   }
 
   try {
@@ -23,14 +23,25 @@ export async function POST(request: Request) {
     return NextResponse.json({ success: true, invitation }, { status: 201 });
   } catch (error) {
     if (error instanceof SyntaxError) {
-      return NextResponse.json({ error: "Geçersiz JSON gövdesi." }, { status: 400 });
+      return NextResponse.json({ error: "clients.detail.invalidRequest" }, { status: 400 });
     }
     if (error instanceof PortalInvitationError) {
       const status = error.code === "FORBIDDEN" ? 403 : error.code === "INVALID_INPUT" ? 400 : 409;
-      return NextResponse.json({ error: error.message, code: error.code }, { status });
+      return NextResponse.json({ error: invitationErrorKey(error.code), code: error.code }, { status });
     }
 
     console.error("Client invitation adapter failed", error);
-    return NextResponse.json({ error: "Müşteri daveti oluşturulamadı." }, { status: 500 });
+    return NextResponse.json({ error: "clients.detail.portalInviteFailed" }, { status: 500 });
+  }
+}
+
+function invitationErrorKey(code: PortalInvitationError["code"]) {
+  switch (code) {
+    case "FORBIDDEN":
+      return "clients.detail.portalInviteForbidden";
+    case "INVALID_INPUT":
+      return "clients.detail.portalInviteInvalid";
+    default:
+      return "clients.detail.portalInviteFailed";
   }
 }