Add folder anatomy (scripts/agent.py + references/api-reference.md) for 648 cybersecurity skills

Complete skill folder anatomy across all cybersecurity skills:
- scripts/agent.py: 80-150 line Python agents using real libraries (impacket,
  boto3, azure-mgmt-*, kubernetes, pefile, yara, scapy, shodan, stix2, etc.)
- references/api-reference.md: real API documentation with method signatures
- LICENSE: MIT license for all skill folders

skills/implementing-continuous-security-validation-with-bas/references/api-reference.md

@@ -0,0 +1,53 @@
+# API Reference: Breach and Attack Simulation Agent
+
+## Dependencies
+
+| Library | Version | Purpose |
+|---------|---------|---------|
+| requests | >=2.28 | HTTP client for SIEM detection validation |
+
+## CLI Usage
+
+```bash
+python scripts/agent.py \
+  --target 10.0.1.50 \
+  --siem-url https://siem.example.com \
+  --siem-key YOUR_KEY \
+  --output-dir /reports/
+```
+
+## Functions
+
+### `simulate_technique(technique, target) -> dict`
+Simulates a MITRE ATT&CK technique and records detection/blocked status.
+
+### `check_siem_detection(siem_url, api_key, technique_id, time_window) -> dict`
+Queries SIEM API for alerts matching the simulated technique within time window.
+
+### `compute_detection_coverage(results) -> dict`
+Calculates overall detection rate and per-tactic coverage breakdown.
+
+### `generate_report(target, siem_url, siem_key) -> dict`
+Runs 7 ATT&CK technique simulations and generates detection gap report.
+
+## ATT&CK Techniques Tested
+
+| ID | Name | Tactic |
+|----|------|--------|
+| T1566.001 | Spearphishing Attachment | Initial Access |
+| T1059.001 | PowerShell | Execution |
+| T1003.001 | LSASS Memory | Credential Access |
+| T1021.002 | SMB Admin Shares | Lateral Movement |
+| T1486 | Data Encrypted for Impact | Impact |
+| T1071.001 | Web Protocols | C2 |
+| T1048.003 | Exfiltration Over Unencrypted | Exfiltration |
+
+## Output Schema
+
+```json
+{
+  "coverage": {"total_tests": 7, "detected": 5, "missed": 2, "detection_rate_pct": 71.4},
+  "gaps": [{"technique_id": "T1003.001", "technique_name": "LSASS Memory"}],
+  "recommendations": ["Create detection rule for T1003.001"]
+}
+```