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>

client/node_modules/nanoid/non-secure/index.js

@@ -0,0 +1,21 @@
+let urlAlphabet =
+  'useandom-26T198340PX75pxJACKVERYMINDBUSHWOLF_GQZbfghjklqvwyzrict'
+let customAlphabet = (alphabet, defaultSize = 21) => {
+  return (size = defaultSize) => {
+    let id = ''
+    let i = size | 0
+    while (i--) {
+      id += alphabet[(Math.random() * alphabet.length) | 0]
+    }
+    return id
+  }
+}
+let nanoid = (size = 21) => {
+  let id = ''
+  let i = size | 0
+  while (i--) {
+    id += urlAlphabet[(Math.random() * 64) | 0]
+  }
+  return id
+}
+export { nanoid, customAlphabet }