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.d.ts

@@ -0,0 +1,33 @@
+/**
+ * Generate URL-friendly unique ID. This method uses the non-secure
+ * predictable random generator with bigger collision probability.
+ *
+ * ```js
+ * import { nanoid } from 'nanoid/non-secure'
+ * model.id = nanoid() //=> "Uakgb_J5m9g-0JDMbcJqL"
+ * ```
+ *
+ * @param size Size of the ID. The default size is 21.
+ * @returns A random string.
+ */
+export function nanoid(size?: number): string
+
+/**
+ * Generate a unique ID based on a custom alphabet.
+ * This method uses the non-secure predictable random generator
+ * with bigger collision probability.
+ *
+ * @param alphabet Alphabet used to generate the ID.
+ * @param defaultSize Size of the ID. The default size is 21.
+ * @returns A random string generator.
+ *
+ * ```js
+ * import { customAlphabet } from 'nanoid/non-secure'
+ * const nanoid = customAlphabet('0123456789абвгдеё', 5)
+ * model.id = //=> "8ё56а"
+ * ```
+ */
+export function customAlphabet(
+  alphabet: string,
+  defaultSize?: number
+): (size?: number) => string