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

.gitignore

@@ -0,0 +1,14 @@
+# API
+api/node_modules
+api/.env
+
+# Web
+web/node_modules
+web/.env
+web/build
+
+# DB
+pgdata
+
+# Env files
+.env