chore: add local design artifacts and gitignore update

Author: darko-mijic

.gitignore

@@ -30,4 +30,7 @@ src/content/docs/delivery-process/generated/
 src/content/docs/delivery-process/tutorial/
 
 # tmp files
-_tmp/  
+_tmp/  
+
+# Local .claude config
+.claude/settings.local.json