Add Milestones 1 & 2: full-stack POS foundation with admin UI

- Node/Express/TypeScript API under /api/v1 with JWT auth (login, refresh, logout, /me)
- Prisma schema: vendors, users, roles, products, categories, taxes, transactions
- SQLite for local dev; Postgres via docker-compose for production
- Full CRUD routes for vendors, users, categories, taxes, products with Zod validation and RBAC
- Paginated list endpoints scoped per vendor; refresh token rotation
- React/TypeScript admin SPA (Vite): login, protected routing, sidebar layout
- Pages: Dashboard, Catalog (tabbed Products/Categories/Taxes), Users, Vendor Settings
- Shared UI: Table, Modal, FormField, Btn, PageHeader components
- Multi-stage Dockerfile; docker-compose with Postgres healthcheck
- Seed script with demo vendor and owner account
- INSTRUCTIONS.md, ROADMAP.md, .claude/launch.json for dev server config

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

server/node_modules/@prisma/engines/README.md

@@ -0,0 +1,13 @@
+# `@prisma/engines`
+
+⚠️ **Warning**: This package is intended for Prisma's internal use.
+Its release cycle does not follow SemVer, which means we might release breaking changes (change APIs, remove functionality) without any prior warning.
+
+The postinstall hook of this package downloads all Prisma engines available for the current platform, namely the Query Engine and the Schema Engine from the Prisma CDN.
+
+The engines version to be downloaded is directly determined by the version of its `@prisma/engines-version` dependency.
+
+You should probably not use this package directly, but instead use one of these:
+
+- [`prisma` CLI](https://www.npmjs.com/package/prisma)
+- [`@prisma/client`](https://www.npmjs.com/package/@prisma/client)