feat(db): add Prisma schema with all models

Configure Prisma ORM with PostgreSQL database schema including:
- Organization, Site, Court models for multi-tenancy
- User with role-based access and Client for customers
- Booking and Payment models for reservations
- MembershipPlan and Membership for subscriptions
- Product, Sale, SaleItem, CashRegister for POS
- Tournament, TournamentInscription, Match for competitions
- All necessary enums, relations, indexes, and cascading deletes
- Prisma client singleton for Next.js

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

apps/web/package.json

@@ -7,9 +7,13 @@
     "build": "next build",
     "start": "next start",
     "lint": "next lint",
-    "type-check": "tsc --noEmit"
+    "type-check": "tsc --noEmit",
+    "db:generate": "prisma generate",
+    "db:push": "prisma db push",
+    "db:studio": "prisma studio"
   },
   "dependencies": {
+    "@prisma/client": "^5.10.0",
     "next": "14.2.0",
     "react": "^18.2.0",
     "react-dom": "^18.2.0"
@@ -20,6 +24,7 @@
     "@types/react-dom": "^18.2.0",
     "autoprefixer": "^10.4.17",
     "postcss": "^8.4.35",
+    "prisma": "^5.10.0",
     "tailwindcss": "^3.4.1",
     "typescript": "^5.3.3"
   }