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/prisma/seed.ts

@@ -0,0 +1,53 @@
+import { PrismaClient } from "@prisma/client";
+import bcrypt from "bcryptjs";
+
+const prisma = new PrismaClient();
+
+async function main() {
+  // Seed roles
+  const ownerRole = await prisma.role.upsert({
+    where: { name: "owner" },
+    update: {},
+    create: { name: "owner" },
+  });
+  await prisma.role.upsert({
+    where: { name: "manager" },
+    update: {},
+    create: { name: "manager" },
+  });
+  await prisma.role.upsert({
+    where: { name: "cashier" },
+    update: {},
+    create: { name: "cashier" },
+  });
+
+  // Seed demo vendor
+  const vendor = await prisma.vendor.upsert({
+    where: { id: "demo-vendor" },
+    update: {},
+    create: {
+      id: "demo-vendor",
+      name: "Demo Store",
+      businessNum: "123-456",
+    },
+  });
+
+  // Seed demo owner user
+  await prisma.user.upsert({
+    where: { email: "admin@demo.com" },
+    update: {},
+    create: {
+      email: "admin@demo.com",
+      passwordHash: await bcrypt.hash("password123", 10),
+      name: "Demo Admin",
+      vendorId: vendor.id,
+      roleId: ownerRole.id,
+    },
+  });
+
+  console.log("Seed complete");
+}
+
+main()
+  .catch(console.error)
+  .finally(() => prisma.$disconnect());