Address code review feedback: add clarifying comments

- Add comment explaining backward compatibility behavior in Registry.register()
- Add comments to PluginSystem tests explaining legacy mode usage
- Clarify that last registration wins for non-namespaced lookups

Co-authored-by: hotlong <50353452+hotlong@users.noreply.github.com>

Author: Copilot

packages/core/src/registry/Registry.ts

@@ -92,6 +92,8 @@ export class Registry<T = any> {
 
     // Also register without namespace for backward compatibility
     // This allows "button" to work even when registered as "ui:button"
+    // Note: If multiple namespaced components share the same short name,
+    // the last registration wins for non-namespaced lookups
     if (meta?.namespace) {
       this.components.set(type, {
         type: fullType, // Keep reference to namespaced type

packages/core/src/registry/__tests__/PluginSystem.test.ts

@@ -28,6 +28,7 @@ describe('PluginSystem', () => {
       }
     };
 
+    // Use legacy mode (useScope: false) to test direct registry access
     await pluginSystem.loadPlugin(plugin, registry, false);
 
     expect(pluginSystem.isLoaded('test-plugin')).toBe(true);
@@ -201,6 +202,7 @@ describe('PluginSystem', () => {
       register: registerFn
     };
 
+    // Use legacy mode (useScope: false) to verify the raw Registry is passed
     await pluginSystem.loadPlugin(plugin, registry, false);
 
     expect(registerFn).toHaveBeenCalledWith(registry);