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/jsonwebtoken/decode.js

@@ -0,0 +1,30 @@
+var jws = require('jws');
+
+module.exports = function (jwt, options) {
+  options = options || {};
+  var decoded = jws.decode(jwt, options);
+  if (!decoded) { return null; }
+  var payload = decoded.payload;
+
+  //try parse the payload
+  if(typeof payload === 'string') {
+    try {
+      var obj = JSON.parse(payload);
+      if(obj !== null && typeof obj === 'object') {
+        payload = obj;
+      }
+    } catch (e) { }
+  }
+
+  //return header if `complete` option is enabled.  header includes claims
+  //such as `kid` and `alg` used to select the key within a JWKS needed to
+  //verify the signature
+  if (options.complete === true) {
+    return {
+      header: decoded.header,
+      payload: payload,
+      signature: decoded.signature
+    };
+  }
+  return payload;
+};