Adopt repository structure

srv/cat-service.cds

@@ -0,0 +1,13 @@
+using { sap.capire.bookshop as my } from '../db/schema';
+
+@path:'/browse'
+service CatalogService {
+
+  @readonly entity Books as SELECT from my.Books {*,
+    author.name as author
+  } excluding { createdBy, modifiedBy };
+
+  @requires_: 'authenticated-user'
+  @insertonly entity Orders as projection on my.Orders;
+
+}