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/upgrade/page.tsx

@@ -92,7 +92,7 @@ function UpgradeContent() {
   const isPro = user?.isPro;
 
   useEffect(() => {
-    if (!loading && !token) router.push("/login");
+    if (!loading && !token) router.push("/auth");
   }, [loading, token, router]);
 
   useEffect(() => {