Initial marketplace implementation

Full-stack marketplace for buying/selling second-hand items.
React 19 + TypeScript + Tailwind CSS v4 frontend with 17 screens,
Express + Prisma + Socket.io backend, Stripe payments, JWT auth.

Deployed at https://marketplace.173.212.212.157.sslip.io/

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

docker-compose.yml

@@ -0,0 +1,16 @@
+services:
+  postgres:
+    image: postgres:16-alpine
+    container_name: marketplace-db
+    restart: unless-stopped
+    ports:
+      - "5432:5432"
+    environment:
+      POSTGRES_USER: marketplace
+      POSTGRES_PASSWORD: marketplace_dev
+      POSTGRES_DB: marketplace
+    volumes:
+      - pgdata:/var/lib/postgresql/data
+
+volumes:
+  pgdata: