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/semver/internal/lrucache.js

@@ -0,0 +1,42 @@
+'use strict'
+
+class LRUCache {
+  constructor () {
+    this.max = 1000
+    this.map = new Map()
+  }
+
+  get (key) {
+    const value = this.map.get(key)
+    if (value === undefined) {
+      return undefined
+    } else {
+      // Remove the key from the map and add it to the end
+      this.map.delete(key)
+      this.map.set(key, value)
+      return value
+    }
+  }
+
+  delete (key) {
+    return this.map.delete(key)
+  }
+
+  set (key, value) {
+    const deleted = this.delete(key)
+
+    if (!deleted && value !== undefined) {
+      // If cache is full, delete the least recently used item
+      if (this.map.size >= this.max) {
+        const firstKey = this.map.keys().next().value
+        this.delete(firstKey)
+      }
+
+      this.map.set(key, value)
+    }
+
+    return this
+  }
+}
+
+module.exports = LRUCache