Initial commit: ozon-mock Go server

- Mock Ozon Seller API endpoints
- Products, Postings, Finance, Returns, Analytics
- JSON fixtures for testing
- Docker support
- Gitea Actions CI/CD

go.mod

@@ -0,0 +1,5 @@
+module github.com/rinat/ozon-mock
+
+go 1.25.0
+
+require github.com/gin-gonic/gin v1.10.0