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/jws/lib/data-stream.js

@@ -0,0 +1,55 @@
+/*global module, process*/
+var Buffer = require('safe-buffer').Buffer;
+var Stream = require('stream');
+var util = require('util');
+
+function DataStream(data) {
+  this.buffer = null;
+  this.writable = true;
+  this.readable = true;
+
+  // No input
+  if (!data) {
+    this.buffer = Buffer.alloc(0);
+    return this;
+  }
+
+  // Stream
+  if (typeof data.pipe === 'function') {
+    this.buffer = Buffer.alloc(0);
+    data.pipe(this);
+    return this;
+  }
+
+  // Buffer or String
+  // or Object (assumedly a passworded key)
+  if (data.length || typeof data === 'object') {
+    this.buffer = data;
+    this.writable = false;
+    process.nextTick(function () {
+      this.emit('end', data);
+      this.readable = false;
+      this.emit('close');
+    }.bind(this));
+    return this;
+  }
+
+  throw new TypeError('Unexpected data type ('+ typeof data + ')');
+}
+util.inherits(DataStream, Stream);
+
+DataStream.prototype.write = function write(data) {
+  this.buffer = Buffer.concat([this.buffer, Buffer.from(data)]);
+  this.emit('data', data);
+};
+
+DataStream.prototype.end = function end(data) {
+  if (data)
+    this.write(data);
+  this.emit('end', data);
+  this.emit('close');
+  this.writable = false;
+  this.readable = false;
+};
+
+module.exports = DataStream;