feat(product-center): implement full product center with NestJS backend, Vue3 admin, and Nuxt4 website page

- NestJS backend: Prisma + PostgreSQL, JWT auth, CRUD for goods/categories/countries/tags/positions, SDS sync with cron, public API, Swagger docs
- Vue3 Admin: Element Plus, goods/categories/countries/tags/positions/sync management pages, batch operations, login with JWT
- Nuxt4 Website: product-center page with sidebar navigation, country filter, search, product grid, pagination, skeleton loading
- Nitro proxy routes for backend API
- 54 backend tests passing
- Updated docs and README

inkreach-official-nestjs/nest-cli.json

@@ -0,0 +1,9 @@
+{
+  "$schema": "https://json.schemastore.org/nest-cli",
+  "collection": "@nestjs/schematics",
+  "sourceRoot": "src",
+  "compilerOptions": {
+    "deleteOutDir": true,
+    "webpack": false
+  }
+}