Map all 754 skills to MITRE ATT&CK v19.1

- Add validated mitre_attack frontmatter to all 754 skills (286 distinct
  techniques), verified against MITRE ATT&CK v19.1 via the official
  mitreattack-python library: 0 revoked, deprecated, or invalid IDs
- Curate precise per-skill technique IDs for forensics, malware-analysis,
  threat-intel, and red-team skills (e.g. DCSync -> T1003.006,
  Kerberoasting -> T1558.003, Pass-the-Ticket -> T1550.003)
- Reconcile v19.1 tactic restructuring: Defense Evasion split into
  Stealth (TA0005) and Defense Impairment (TA0112); revoked T1562.*
  family and T1070.001/.002 remapped to active equivalents (T1685.*)
- Normalize word-split tags across 35 skills (remove filename-derived
  stopword tags, add semantic cybersecurity tags)
- Add api-reference.md for 3 skills that were missing it
- Update README ATT&CK section with accurate v19.1 tactic distribution

skills/implementing-kubernetes-pod-security-standards/SKILL.md

@@ -1,7 +1,8 @@
 ---
 name: implementing-kubernetes-pod-security-standards
-description: Pod Security Standards (PSS) define three levels of security policies -- Privileged, Baseline, and Restricted
-  -- enforced by the Pod Security Admission (PSA) controller built into Kubernetes 1.25+. PS
+description: Pod Security Standards (PSS) define three levels of security policies
+  -- Privileged, Baseline, and Restricted -- enforced by the Pod Security Admission
+  (PSA) controller built into Kubernetes 1.25+. PS
 domain: cybersecurity
 subdomain: container-security
 tags:
@@ -18,6 +19,11 @@ nist_csf:
 - PR.IR-01
 - ID.AM-08
 - DE.CM-01
+mitre_attack:
+- T1610
+- T1611
+- T1609
+- T1525
 ---
 # Implementing Kubernetes Pod Security Standards