Enforce protected attribute encapsulation in specs

- Add tests to ensure internal attributes (`collection`, `storage`, and `data`) in `Hooks::Collection`, `Settings::Collection`, `RegistrySettings`, and `Settings::Setting` remain inaccessible via public interface.
- Verify `NoMethodError` is raised when attempting public access to these protected attributes.

Author: afuno

spec/stroma/hooks/collection_spec.rb

@@ -110,4 +110,10 @@
       expect(hooks.map(&:itself)).to all(be_a(Stroma::Hooks::Hook))
     end
   end
+
+  describe "protected interface" do
+    it "does not expose collection publicly" do
+      expect { hooks.collection }.to raise_error(NoMethodError)
+    end
+  end
 end

spec/stroma/settings/collection_spec.rb

@@ -138,4 +138,10 @@
       expect(settings[:actions][:transactional][:class]).to eq("ActiveRecord::Base")
     end
   end
+
+  describe "protected interface" do
+    it "does not expose storage publicly" do
+      expect { settings.storage }.to raise_error(NoMethodError)
+    end
+  end
 end

spec/stroma/settings/registry_settings_spec.rb

@@ -109,4 +109,10 @@
       expect(settings[:authorization].key?(:new_key)).to be(false)
     end
   end
+
+  describe "protected interface" do
+    it "does not expose storage publicly" do
+      expect { settings.storage }.to raise_error(NoMethodError)
+    end
+  end
 end

spec/stroma/settings/setting_spec.rb

@@ -146,4 +146,10 @@
       expect(setting[:list][1][0]).to eq(2)
     end
   end
+
+  describe "protected interface" do
+    it "does not expose data publicly" do
+      expect { setting.data }.to raise_error(NoMethodError)
+    end
+  end
 end