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/extracting-credentials-from-memory-dump/SKILL.md

@@ -1,7 +1,7 @@
 ---
 name: extracting-credentials-from-memory-dump
-description: Extract cached credentials, password hashes, Kerberos tickets, and authentication tokens from memory dumps using
-  Volatility and Mimikatz for forensic investigation.
+description: Extract cached credentials, password hashes, Kerberos tickets, and authentication
+  tokens from memory dumps using Volatility and Mimikatz for forensic investigation.
 domain: cybersecurity
 subdomain: digital-forensics
 tags:
@@ -13,9 +13,11 @@ tags:
 - password-hashes
 - incident-response
 mitre_attack:
+- T1005
+- T1074
+- T1119
+- T1070
 - T1003
-- T1558
-- T1552
 version: '1.0'
 author: mahipal
 license: Apache-2.0