feat: Full petmaster CRM with NestJS API and React frontend

- Client management (CRUD with JSONB custom fields)
- Pet profiles
- Service catalog with per-client pricing
- Booking calendar with recurring appointments
- Invoicing with Stripe integration
- Real-time messaging (WebSocket)
- Self-booking portal
- Staff assignment
- Docker multi-stage builds
- Prisma schema + seed

DOCKER.md

@@ -0,0 +1,61 @@
+# Petmaster CRM - Docker Compose Setup
+
+## Quick Start
+
+Start all services:
+  docker compose up --build
+
+Or detached mode:
+  docker compose up -d --build
+
+Services will be available at:
+- Frontend: http://localhost:3001
+- API: http://localhost:3000
+- API Docs: http://localhost:3000/api/docs
+- PostgreSQL: localhost:5432
+
+## Configuration
+
+Copy and configure environment:
+  cp .env.example .env
+  cp api/.env.example api/.env
+
+Edit .env with your settings:
+  STRIPE_SECRET_KEY=sk_live_your_key_here
+  JWT_SECRET=your_secure_secret
+
+## Stop Services
+
+Remove containers:
+  docker compose down
+
+Remove containers and volumes:
+  docker compose down -v
+
+## Database
+
+Run migrations manually:
+  docker compose exec api npx prisma migrate dev --name init
+
+Seed the database:
+  docker compose exec api npx prisma db seed
+
+## Development
+
+The API has hot-reload enabled via volume mount (./api/src:/app/src).
+Changes to TypeScript files will automatically restart the NestJS server.
+
+The frontend uses react-scripts for development with hot reload.
+
+## Production
+
+For production deployment:
+
+1. Set production environment variables
+2. Use multi-stage Docker builds (already configured)
+3. Consider adding:
+   - Reverse proxy (nginx/traefik)
+   - SSL certificates (Let's Encrypt)
+   - Redis for WebSocket scaling
+   - SMTP for email notifications
+   - Stripe webhook endpoint