Referral page, bug fixes, seed data, persona tiers

- New /refer page with share/copy/stats
- Fixed modal z-index conflicts (z-50 → z-[60]) across forum, groups, souq, halal-monitor
- Seed route: forum categories, marketplace listings, private groups
- Mufti/Daie personas now available in Premium tier
- Fixed referral share link: falahos.my/mobile/auth?ref=CODE
- Fixed client-side persona access check for premium

src/app/groups/[id]/page.tsx

@@ -124,7 +124,7 @@ export default function GroupDetailPage() {
 
   useEffect(() => {
     if (!loading && !token) {
-      router.push("/login");
+      router.push("/auth");
       return;
     }
   }, [loading, token, router]);

src/app/groups/page.tsx

@@ -94,7 +94,7 @@ export default function GroupsPage() {
 
   useEffect(() => {
     if (!loading && !token) {
-      router.push("/login");
+      router.push("/auth");
       return;
     }
   }, [loading, token, router]);
@@ -362,7 +362,7 @@ export default function GroupsPage() {
 
       {/* Create group modal */}
       {showCreateModal && (
-        <div className="fixed inset-0 z-50 flex items-end sm:items-center justify-center">
+        <div className="fixed inset-0 z-[60] flex items-end sm:items-center justify-center">
           <div
             className="absolute inset-0 bg-black/60 backdrop-blur-sm"
             onClick={() => setShowCreateModal(false)}
@@ -447,7 +447,7 @@ export default function GroupsPage() {
 
       {/* Join group modal */}
       {showJoinModal && (
-        <div className="fixed inset-0 z-50 flex items-end sm:items-center justify-center">
+        <div className="fixed inset-0 z-[60] flex items-end sm:items-center justify-center">
           <div
             className="absolute inset-0 bg-black/60 backdrop-blur-sm"
             onClick={() => {