feat: add ESP32 DIY platform Phase 1 (marketplace scaffold)

- Docker Compose with Postgres, Redis, MinIO, backend, frontend (port 3200/3201)
- Prisma schema: User, Project, ProjectFile, Product, Order, FlashToken, Review, AuditLog
- Backend: JWT auth, project CRUD + file upload (MinIO + sharp WebP), admin approval flow
- Frontend: React + Vite SPA with auth, project/shop browse, seller dashboard, admin panel
- Admin: pending approval queue, user management, audit log viewer, stats dashboard
- Audit logging middleware for legal compliance
- Admin init script: createAdmin.js
- Full design document in PLATFORM_DESIGN.md

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

platform/backend/package.json

@@ -0,0 +1,32 @@
+{
+  "name": "platform-backend",
+  "version": "1.0.0",
+  "type": "commonjs",
+  "scripts": {
+    "start": "node src/index.js",
+    "dev": "nodemon src/index.js",
+    "db:migrate": "prisma migrate deploy",
+    "db:generate": "prisma generate",
+    "db:push": "prisma db push",
+    "postinstall": "prisma generate"
+  },
+  "dependencies": {
+    "@prisma/client": "^5.14.0",
+    "bcryptjs": "^2.4.3",
+    "cors": "^2.8.5",
+    "express": "^4.19.2",
+    "express-rate-limit": "^7.3.1",
+    "express-validator": "^7.1.0",
+    "helmet": "^7.1.0",
+    "ioredis": "^5.4.1",
+    "jsonwebtoken": "^9.0.2",
+    "minio": "^8.0.0",
+    "multer": "^1.4.5-lts.1",
+    "sharp": "^0.33.4",
+    "uuid": "^10.0.0"
+  },
+  "devDependencies": {
+    "nodemon": "^3.1.4",
+    "prisma": "^5.14.0"
+  }
+}