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>

.claude/launch.json

@@ -0,0 +1,17 @@
+{
+  "version": "0.0.1",
+  "configurations": [
+    {
+      "name": "API Server",
+      "runtimeExecutable": "node",
+      "runtimeArgs": ["C:/Program Files/nodejs/node_modules/npm/bin/npm-cli.js", "--prefix", "server", "run", "dev"],
+      "port": 8080
+    },
+    {
+      "name": "Admin UI (Vite)",
+      "runtimeExecutable": "node",
+      "runtimeArgs": ["C:/Program Files/nodejs/node_modules/npm/bin/npm-cli.js", "--prefix", "client", "run", "dev"],
+      "port": 5173
+    }
+  ]
+}