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-hash-cracking-with-hashcat/SKILL.md

@@ -1,8 +1,9 @@
 ---
 name: performing-hash-cracking-with-hashcat
-description: Hash cracking is an essential skill for penetration testers and security
-  auditors to evaluate password strength. Hashcat is the world's fastest password
-  recovery tool, supporting over 300 hash types w
+description: Cracks password hashes with Hashcat, covering hash-type identification,
+  dictionary/brute-force/rule-based attack modes, custom rule creation, GPU benchmarking,
+  and password-strength/compliance reporting. Use for authorized penetration testing
+  or security audits that need to evaluate password strength or crack captured hashes.
 domain: cybersecurity
 subdomain: cryptography
 tags: