Remove backed-up duplicate skills to fix validation pipeline

skills/analyzing-windows-shellbag-artifacts/SKILL.md

@@ -15,6 +15,21 @@ license: Apache-2.0
 
 Shellbags are Windows registry artifacts that track how users interact with folders through Windows Explorer, storing view settings such as icon size, window position, sort order, and view mode. From a forensic perspective, Shellbags provide definitive evidence of folder access -- even folders that no longer exist on the system. When a user browses to a folder via Windows Explorer, the Open/Save dialog, or the Control Panel, a Shellbag entry is created or updated in the user's registry hive. These entries persist after folder deletion, drive disconnection, and even across user profile resets, making them invaluable for proving that a user navigated to specific directories on local drives, USB devices, network shares, or zip archives.
 
+
+## When to Use
+
+- When investigating security incidents that require analyzing windows shellbag artifacts
+- When building detection rules or threat hunting queries for this domain
+- When SOC analysts need structured procedures for this analysis type
+- When validating security monitoring coverage for related attack techniques
+
+## Prerequisites
+
+- Familiarity with digital forensics concepts and tools
+- Access to a test or lab environment for safe execution
+- Python 3.8+ with required dependencies installed
+- Appropriate authorization for any testing activities
+
 ## Registry Locations
 
 ### Windows 7/8/10/11