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/side-channel/index.d.ts

@@ -0,0 +1,14 @@
+import getSideChannelList from 'side-channel-list';
+import getSideChannelMap from 'side-channel-map';
+import getSideChannelWeakMap from 'side-channel-weakmap';
+
+declare namespace getSideChannel {
+	type Channel<K, V> =
+		| getSideChannelList.Channel<K, V>
+		| ReturnType<Exclude<typeof getSideChannelMap<K, V>, false>>
+		| ReturnType<Exclude<typeof getSideChannelWeakMap<K, V>, false>>;
+}
+
+declare function getSideChannel<K, V>(): getSideChannel.Channel<K, V>;
+
+export = getSideChannel;