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/client/schema.prisma

@@ -0,0 +1,134 @@
+generator client {
+  provider = "prisma-client-js"
+}
+
+datasource db {
+  provider = "sqlite"
+  url      = env("DATABASE_URL")
+}
+
+model Vendor {
+  id          String   @id @default(cuid())
+  name        String
+  businessNum String?
+  taxSettings String? // JSON string
+  createdAt   DateTime @default(now())
+  updatedAt   DateTime @updatedAt
+
+  users        User[]
+  categories   Category[]
+  products     Product[]
+  taxes        Tax[]
+  transactions Transaction[]
+}
+
+model Role {
+  id   String @id @default(cuid())
+  name String @unique // cashier | manager | owner
+
+  users User[]
+}
+
+model User {
+  id           String   @id @default(cuid())
+  email        String   @unique
+  passwordHash String
+  name         String
+  vendorId     String
+  roleId       String
+  createdAt    DateTime @default(now())
+  updatedAt    DateTime @updatedAt
+
+  vendor        Vendor         @relation(fields: [vendorId], references: [id])
+  role          Role           @relation(fields: [roleId], references: [id])
+  refreshTokens RefreshToken[]
+  transactions  Transaction[]
+}
+
+model RefreshToken {
+  id        String   @id @default(cuid())
+  token     String   @unique
+  userId    String
+  expiresAt DateTime
+  createdAt DateTime @default(now())
+
+  user User @relation(fields: [userId], references: [id], onDelete: Cascade)
+}
+
+model Category {
+  id        String   @id @default(cuid())
+  name      String
+  vendorId  String
+  createdAt DateTime @default(now())
+  updatedAt DateTime @updatedAt
+
+  vendor   Vendor    @relation(fields: [vendorId], references: [id])
+  products Product[]
+}
+
+model Tax {
+  id        String   @id @default(cuid())
+  name      String
+  rate      Float
+  vendorId  String
+  createdAt DateTime @default(now())
+  updatedAt DateTime @updatedAt
+
+  vendor   Vendor    @relation(fields: [vendorId], references: [id])
+  products Product[]
+}
+
+model Product {
+  id          String   @id @default(cuid())
+  name        String
+  sku         String?
+  description String?
+  price       Float
+  vendorId    String
+  categoryId  String?
+  taxId       String?
+  tags        String? // comma-separated or JSON string
+  version     Int      @default(1)
+  createdAt   DateTime @default(now())
+  updatedAt   DateTime @updatedAt
+
+  vendor           Vendor            @relation(fields: [vendorId], references: [id])
+  category         Category?         @relation(fields: [categoryId], references: [id])
+  tax              Tax?              @relation(fields: [taxId], references: [id])
+  transactionItems TransactionItem[]
+}
+
+model Transaction {
+  id             String   @id @default(cuid())
+  idempotencyKey String   @unique
+  vendorId       String
+  userId         String
+  status         String // pending | completed | failed | refunded
+  paymentMethod  String // cash | card
+  subtotal       Float
+  taxTotal       Float
+  discountTotal  Float
+  total          Float
+  notes          String?
+  createdAt      DateTime @default(now())
+  updatedAt      DateTime @updatedAt
+
+  vendor Vendor            @relation(fields: [vendorId], references: [id])
+  user   User              @relation(fields: [userId], references: [id])
+  items  TransactionItem[]
+}
+
+model TransactionItem {
+  id            String @id @default(cuid())
+  transactionId String
+  productId     String
+  productName   String
+  quantity      Int
+  unitPrice     Float
+  taxRate       Float
+  discount      Float
+  total         Float
+
+  transaction Transaction @relation(fields: [transactionId], references: [id])
+  product     Product     @relation(fields: [productId], references: [id])
+}