feat: add chat topic

app/dashboard/questions/page.tsx

@@ -20,10 +20,17 @@ import { toFa } from "@/lib/utils";
 interface Question {
   id: number;
   title?: string;
-  category?: string;
+  // Submitted as a string (name); returned by the API as a related object.
+  category?: { id?: number; name?: string } | string | null;
   tags?: string[] | string;
 }
 
+function categoryName(c: Question["category"]): string {
+  if (!c) return "";
+  if (typeof c === "string") return c;
+  return c.name ?? "";
+}
+
 function asTags(value: Question["tags"]): string[] {
   if (Array.isArray(value)) return value.map((t) => String(t));
   if (typeof value === "string" && value.trim() !== "") {
@@ -73,7 +80,7 @@ export default function QuestionsPage() {
   function openEdit(row: Question) {
     setEditing(row);
     setTitle(row.title ?? "");
-    setCategory(row.category ?? "");
+    setCategory(categoryName(row.category));
     setTagsInput(asTags(row.tags).join("، "));
     setOpen(true);
   }
@@ -125,7 +132,7 @@ export default function QuestionsPage() {
   const columns: Column<Question>[] = [
     { key: "id", header: "شناسه", render: (r) => toFa(r.id), className: "w-20" },
     { key: "title", header: "عنوان", render: (r) => r.title ?? "—" },
-    { key: "category", header: "دسته", render: (r) => r.category ?? "—" },
+    { key: "category", header: "دسته", render: (r) => categoryName(r.category) || "—" },
     {
       key: "tags",
       header: "برچسب‌ها",