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/negotiator/index.js

@@ -0,0 +1,82 @@
+/*!
+ * negotiator
+ * Copyright(c) 2012 Federico Romero
+ * Copyright(c) 2012-2014 Isaac Z. Schlueter
+ * Copyright(c) 2015 Douglas Christopher Wilson
+ * MIT Licensed
+ */
+
+'use strict';
+
+var preferredCharsets = require('./lib/charset')
+var preferredEncodings = require('./lib/encoding')
+var preferredLanguages = require('./lib/language')
+var preferredMediaTypes = require('./lib/mediaType')
+
+/**
+ * Module exports.
+ * @public
+ */
+
+module.exports = Negotiator;
+module.exports.Negotiator = Negotiator;
+
+/**
+ * Create a Negotiator instance from a request.
+ * @param {object} request
+ * @public
+ */
+
+function Negotiator(request) {
+  if (!(this instanceof Negotiator)) {
+    return new Negotiator(request);
+  }
+
+  this.request = request;
+}
+
+Negotiator.prototype.charset = function charset(available) {
+  var set = this.charsets(available);
+  return set && set[0];
+};
+
+Negotiator.prototype.charsets = function charsets(available) {
+  return preferredCharsets(this.request.headers['accept-charset'], available);
+};
+
+Negotiator.prototype.encoding = function encoding(available) {
+  var set = this.encodings(available);
+  return set && set[0];
+};
+
+Negotiator.prototype.encodings = function encodings(available) {
+  return preferredEncodings(this.request.headers['accept-encoding'], available);
+};
+
+Negotiator.prototype.language = function language(available) {
+  var set = this.languages(available);
+  return set && set[0];
+};
+
+Negotiator.prototype.languages = function languages(available) {
+  return preferredLanguages(this.request.headers['accept-language'], available);
+};
+
+Negotiator.prototype.mediaType = function mediaType(available) {
+  var set = this.mediaTypes(available);
+  return set && set[0];
+};
+
+Negotiator.prototype.mediaTypes = function mediaTypes(available) {
+  return preferredMediaTypes(this.request.headers.accept, available);
+};
+
+// Backwards compatibility
+Negotiator.prototype.preferredCharset = Negotiator.prototype.charset;
+Negotiator.prototype.preferredCharsets = Negotiator.prototype.charsets;
+Negotiator.prototype.preferredEncoding = Negotiator.prototype.encoding;
+Negotiator.prototype.preferredEncodings = Negotiator.prototype.encodings;
+Negotiator.prototype.preferredLanguage = Negotiator.prototype.language;
+Negotiator.prototype.preferredLanguages = Negotiator.prototype.languages;
+Negotiator.prototype.preferredMediaType = Negotiator.prototype.mediaType;
+Negotiator.prototype.preferredMediaTypes = Negotiator.prototype.mediaTypes;