fix: require open drawer to complete transactions, fix product price field

- Backend enforces open drawer at location before completing any transaction
- Frontend disables payment buttons when drawer is closed with warning message
- Fix product price field name (price, not sellingPrice) in POS API types
- Fix seed UUIDs to use valid UUID v4 format (version nibble must be 1-8)
- Fix Vite allowedHosts for dev.lunarfront.tech access
- Add e2e test for drawer enforcement (39 POS tests now pass)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

packages/admin/vite.config.ts

@@ -17,6 +17,7 @@ export default defineConfig({
   },
   server: {
     port: 5173,
+    allowedHosts: ['dev.lunarfront.tech'],
     proxy: {
       '/v1': {
         target: 'http://localhost:8000',