Rewrite 548 skill descriptions to the activation rubric

Each rewritten description now states both what the skill does (concrete
capability, named tools/artifacts) and an explicit when-to-use trigger,
improving agent discovery/activation. Grounded in each skill's own body;
changes confined to the `description` field only (bodies and all other
frontmatter untouched). Produced by a gated audit->rewrite->recheck loop
(548 -> 0 flagged) with a sampled anti-invention check (0 ungrounded).

Schema: 817/817 pass. Framework-ID gate: 0 defects.

skills/performing-disk-forensics-investigation/SKILL.md

@@ -1,11 +1,10 @@
 ---
 name: performing-disk-forensics-investigation
-description: 'Conducts disk forensics investigations using forensic imaging, file
-  system analysis, artifact recovery, and timeline reconstruction to support incident
-  response cases. Utilizes tools such as FTK Imager, Autopsy, and The Sleuth Kit for
-  evidence acquisition, deleted file recovery, and artifact examination. Activates
-  for requests involving disk forensics, hard drive analysis, forensic imaging, file
-  recovery, evidence acquisition, or digital forensic investigation.
+description: 'Conduct disk forensics investigations using forensic imaging, file system
+  analysis, and timeline reconstruction, with tools such as FTK Imager, Autopsy, and
+  The Sleuth Kit, for evidence acquisition, deleted file recovery, and artifact examination.
+  Use when a security incident requires forensic analysis of persistent storage or
+  when evidence must be preserved for legal or HR proceedings.
 
   '
 domain: cybersecurity