docs(skills): rewrite container-security descriptions to a uniform standard

All 33 container-security skills now carry what it does, an explicit
"Use when" trigger, keywords, and a negative trigger naming the nearest
neighbour. Six collision clusters resolved by differentiating scope
rather than merging, so no skill is removed:

- kube-bench: running the tool vs interpreting findings into an audit
- Calico: portable upstream NetworkPolicy vs Calico-as-CNI vs Calico-only
  CRDs (GlobalNetworkPolicy, HostEndpoint, DNS egress)
- Falco: deploying and operating it vs authoring escape rules
- container escape: tool-agnostic runtime signals vs Falco rule syntax vs
  static posture audit vs offensive breakout
- Trivy: all-target platform and operator vs single-image scan
- Docker: images and Dockerfiles vs daemon.json vs the CIS audit script

Also replaces the templated "When to Use" boilerplate in these files,
including bullets that only restated the skill's own name.

Worst pair (Pod Security Standards vs Pod Security Admission) drops from
0.77 cosine to below the 0.45 threshold. Repo-wide: colliding pairs
60 -> 56, skills involved 105 -> 94.

skills/benchmarking-kubernetes-with-kube-bench/SKILL.md

@@ -1,6 +1,14 @@
 ---
 name: benchmarking-kubernetes-with-kube-bench
-description: Run kube-bench (Aqua Security) against a Kubernetes cluster's control-plane, kubelet, and node configuration to check compliance with the CIS Kubernetes Benchmark and remediate PASS/FAIL/WARN findings. Use when establishing a security baseline for a new cluster, performing periodic hardening audits, validating remediation after configuration changes, or gathering compliance evidence for SOC 2/PCI DSS.
+description: >-
+  Installs and runs the kube-bench tool against a Kubernetes cluster as a Job, DaemonSet, or
+  standalone binary, selecting the correct benchmark version and targets (control plane, etcd,
+  kubelet, worker nodes) and emitting JSON or JUnit output for pipelines. Use when setting
+  kube-bench up for the first time, choosing which benchmark version and node targets to run,
+  wiring it into CI, or troubleshooting skipped or misdetected checks. Keywords: kube-bench,
+  DaemonSet, --benchmark, --targets, JSON output, JUnit, CI integration. Do not use for
+  interpreting the findings or producing an audit report - use
+  performing-kubernetes-cis-benchmark-with-kube-bench.
 domain: cybersecurity
 subdomain: container-security
 tags: