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/dunder-proto/set.js

@@ -0,0 +1,35 @@
+'use strict';
+
+var callBind = require('call-bind-apply-helpers');
+var gOPD = require('gopd');
+var $TypeError = require('es-errors/type');
+
+/** @type {{ __proto__?: object | null }} */
+var obj = {};
+try {
+	obj.__proto__ = null; // eslint-disable-line no-proto
+} catch (e) {
+	if (!e || typeof e !== 'object' || !('code' in e) || e.code !== 'ERR_PROTO_ACCESS') {
+		throw e;
+	}
+}
+
+var hasProtoMutator = !('toString' in obj);
+
+// eslint-disable-next-line no-extra-parens
+var desc = gOPD && gOPD(Object.prototype, /** @type {keyof typeof Object.prototype} */ ('__proto__'));
+
+/** @type {import('./set')} */
+module.exports = hasProtoMutator && (
+// eslint-disable-next-line no-extra-parens
+	(!!desc && typeof desc.set === 'function' && /** @type {import('./set')} */ (callBind([desc.set])))
+	|| /** @type {import('./set')} */ function setDunder(object, proto) {
+		// this is node v0.10 or older, which doesn't have Object.setPrototypeOf and has undeniable __proto__
+		if (object == null) { // eslint-disable-line eqeqeq
+			throw new $TypeError('set Object.prototype.__proto__ called on null or undefined');
+		}
+		// eslint-disable-next-line no-proto, no-param-reassign, no-extra-parens
+		/** @type {{ __proto__?: object | null }} */ (object).__proto__ = proto;
+		return proto;
+	}
+);