Add resource definitions for all 22 API tags, wire client accessors and require tree

lib/fiken/resources/products.rb

@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+module Fiken
+  module Resources
+    # /companies/{slug}/products
+    class Products < Resource::Base
+      include Resource::Listable
+      include Resource::Findable
+      include Resource::Creatable
+      include Resource::Updatable # PUT
+      include Resource::Deletable
+
+      def resource_path
+        "products"
+      end
+
+      # POST /products/salesReport — returns an array of per-product report rows.
+      def sales_report(attributes)
+        body = connection.post("#{base_path}/salesReport", attributes).body
+        Array(body).map { |row| wrap(row) }
+      end
+    end
+  end
+end