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/inherits/inherits_browser.js

@@ -0,0 +1,27 @@
+if (typeof Object.create === 'function') {
+  // implementation from standard node.js 'util' module
+  module.exports = function inherits(ctor, superCtor) {
+    if (superCtor) {
+      ctor.super_ = superCtor
+      ctor.prototype = Object.create(superCtor.prototype, {
+        constructor: {
+          value: ctor,
+          enumerable: false,
+          writable: true,
+          configurable: true
+        }
+      })
+    }
+  };
+} else {
+  // old school shim for old browsers
+  module.exports = function inherits(ctor, superCtor) {
+    if (superCtor) {
+      ctor.super_ = superCtor
+      var TempCtor = function () {}
+      TempCtor.prototype = superCtor.prototype
+      ctor.prototype = new TempCtor()
+      ctor.prototype.constructor = ctor
+    }
+  }
+}