feat: Souq native integration + auth simplification + CE-wide enhancements

Souq Marketplace:
- Native souq pages: browse+filters, create listing, detail+seller profile, orders+chat
- New API: reviews (POST), sellers/[id], upload (multipart), polar-checkout webhook
- Listings API enhanced: minPrice, maxPrice, sortBy, deliveryDays filters
- Seller workflow: start order, mark delivered, upload files, confirm delivery
- Wallet: 5 Polar.sh FLH tiers, production checkout, mock fallback, success banner
- Fix: order redirect /souq/history → /souq/orders

Auth System:
- Unified auth page, removed OAuth provider routing (2 files deleted)
- Deleted oauth.ts (319 lines) — simplified auth chain
- Streamlined login/register API routes

Prisma Schema (+179 lines):
- New models: Listing, Purchase, Review, Group/GroupMember
- Gamification: DailyStreak, XpTransaction, Achievement, UserLevel
- Learning: LearnCourse/Module/Enrollment/Certificate
- Notifications, Referrals, Dhikr, PremiumBenefits

Deleted legacy code:
- src/app/api/marketplace/* (3 files) — replaced by /api/souq/*
- src/app/api/files/[listingId]/route.ts — replaced by /api/souq/upload
- src/app/api/seller/[sellerId]/route.ts — replaced by /api/souq/sellers/[id]

Infrastructure:
- Dockerfile: standalone output, Prisma runtime migration
- docker-compose.yml: Polar env vars, healthcheck fix
- docker-compose.staging.yml: staging on port 4014
- .gitea/workflows/ci.yml: CI pipeline

src/app/page.tsx

@@ -384,15 +384,25 @@ export default function HomePage() {
   );
 }
 
-function QuickAction({ href, icon: Icon, label, color }: { href: string; icon: any; label: string; color: string }) {
-  return (
-    <Link href={href} className="flex flex-col items-center gap-1.5 active:scale-95 transition">
+function QuickAction({ href, icon: Icon, label, color, external }: { href: string; icon: any; label: string; color: string; external?: boolean }) {
+  const content = (
+    <div className="flex flex-col items-center gap-1.5 active:scale-95 transition">
       <div className={`w-14 h-14 rounded-2xl flex items-center justify-center ${color} bg-opacity-20`}>
         <Icon size={22} />
       </div>
       <span className="text-xs text-gray-500 font-medium">{label}</span>
-    </Link>
+    </div>
   );
+
+  if (external) {
+    return (
+      <a href={href} target="_blank" rel="noopener noreferrer" className="active:scale-95 transition">
+        {content}
+      </a>
+    );
+  }
+
+  return <Link href={href} className="active:scale-95 transition">{content}</Link>;
 }
 
 function StatCard({ label, value, icon: Icon, color }: { label: string; value: string; icon: any; color: string }) {