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/analyzing-windows-prefetch-with-python/SKILL.md

@@ -1,8 +1,10 @@
 ---
 name: analyzing-windows-prefetch-with-python
-description: Parse Windows Prefetch files using the windowsprefetch Python library
-  to reconstruct application execution history, detect renamed or masquerading binaries,
-  and identify suspicious program execution patterns.
+description: Parse Windows Prefetch (.pf) files with the windowsprefetch Python
+  library to reconstruct application execution history, run counts, and accessed
+  file/volume lists. Use when investigating renamed or masquerading binaries, verifying
+  program execution timelines, or hunting for suspicious execution patterns in incident
+  response.
 domain: cybersecurity
 subdomain: digital-forensics
 tags: