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/reverse-engineering-malware-with-ghidra/SKILL.md

@@ -1,10 +1,10 @@
 ---
 name: reverse-engineering-malware-with-ghidra
-description: 'Reverse engineers malware binaries using NSA''s Ghidra disassembler
-  and decompiler to understand internal logic, cryptographic routines, C2 protocols,
-  and evasion techniques at the assembly and pseudo-C level. Activates for requests
-  involving malware reverse engineering, disassembly analysis, decompilation, binary
-  analysis, or understanding malware internals.
+description: 'Reverse engineers malware binaries using NSA''s Ghidra disassembler and
+  decompiler to study internal logic, cryptographic routines, C2 protocols, and evasion
+  techniques at the assembly and pseudo-C level. Use when static or dynamic analysis
+  flags suspicious functionality needing deeper code review, such as reversing C2
+  protocols, encryption algorithms, custom obfuscation, or a sample''s exploit mechanism.
 
   '
 domain: cybersecurity