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/implementing-pod-security-admission-controller/SKILL.md

@@ -1,7 +1,10 @@
 ---
 name: implementing-pod-security-admission-controller
-description: Implement Kubernetes Pod Security Admission to enforce baseline and restricted
-  security profiles at namespace level using built-in admission controller.
+description: Implement Kubernetes Pod Security Admission (PSA), the built-in admission
+  controller stable since v1.25, to enforce Privileged, Baseline, and Restricted
+  Pod Security Standards at the namespace level with enforce, audit, and warn modes,
+  replacing the deprecated PodSecurityPolicy. Use when hardening Kubernetes namespaces,
+  migrating off PodSecurityPolicy, or enforcing pod-level security baselines.
 domain: cybersecurity
 subdomain: container-security
 tags: