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>

client/tsconfig.app.json

@@ -0,0 +1,26 @@
+{
+  "compilerOptions": {
+    "tsBuildInfoFile": "./node_modules/.tmp/tsconfig.app.tsbuildinfo",
+    "target": "ES2022",
+    "useDefineForClassFields": true,
+    "lib": ["ES2022", "DOM", "DOM.Iterable"],
+    "module": "ESNext",
+    "types": ["vite/client"],
+    "skipLibCheck": true,
+    "moduleResolution": "bundler",
+    "allowImportingTsExtensions": true,
+    "verbatimModuleSyntax": true,
+    "moduleDetection": "force",
+    "noEmit": true,
+    "jsx": "react-jsx",
+    "strict": true,
+    "noUnusedLocals": true,
+    "noUnusedParameters": true,
+    "noFallthroughCasesInSwitch": true,
+    "paths": {
+      "@/*": ["./src/*"]
+    },
+    "baseUrl": "."
+  },
+  "include": ["src"]
+}