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/unpipe/index.js

@@ -0,0 +1,69 @@
+/*!
+ * unpipe
+ * Copyright(c) 2015 Douglas Christopher Wilson
+ * MIT Licensed
+ */
+
+'use strict'
+
+/**
+ * Module exports.
+ * @public
+ */
+
+module.exports = unpipe
+
+/**
+ * Determine if there are Node.js pipe-like data listeners.
+ * @private
+ */
+
+function hasPipeDataListeners(stream) {
+  var listeners = stream.listeners('data')
+
+  for (var i = 0; i < listeners.length; i++) {
+    if (listeners[i].name === 'ondata') {
+      return true
+    }
+  }
+
+  return false
+}
+
+/**
+ * Unpipe a stream from all destinations.
+ *
+ * @param {object} stream
+ * @public
+ */
+
+function unpipe(stream) {
+  if (!stream) {
+    throw new TypeError('argument stream is required')
+  }
+
+  if (typeof stream.unpipe === 'function') {
+    // new-style
+    stream.unpipe()
+    return
+  }
+
+  // Node.js 0.8 hack
+  if (!hasPipeDataListeners(stream)) {
+    return
+  }
+
+  var listener
+  var listeners = stream.listeners('close')
+
+  for (var i = 0; i < listeners.length; i++) {
+    listener = listeners[i]
+
+    if (listener.name !== 'cleanup' && listener.name !== 'onclose') {
+      continue
+    }
+
+    // invoke the listener
+    listener.call(stream)
+  }
+}