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/performing-web-application-firewall-bypass/references/api-reference.md

@@ -0,0 +1,53 @@
+# API Reference: WAF Bypass Testing
+
+## Encoding Bypass Techniques
+
+| Technique | Example | Description |
+|-----------|---------|-------------|
+| URL Encoding | `%3Cscript%3E` | Single URL encode |
+| Double Encoding | `%253Cscript%253E` | Double URL encode |
+| Unicode/Fullwidth | `\uff1cscript\uff1e` | Unicode replacement |
+| HTML Entities | `<script>` | Hex HTML entities |
+| Null Byte | `%00` insertion | Terminate string parsing |
+| Tab/Newline | `scr\tipt` | Whitespace insertion |
+
+## SQLi WAF Bypass Techniques
+
+| Technique | Payload Pattern |
+|-----------|----------------|
+| Inline Comment | `1'/**/OR/**/1=1--` |
+| Version Comment | `1'/*!50000OR*/1=1--` |
+| Case Variation | `1' oR 1=1--` |
+| Hex Encoding | `0x313d31` |
+| Buffer Overflow | Long padding before payload |
+| Content-Type Switch | Send as `application/json` |
+
+## HTTP Method Bypass
+
+| Method | WAF Behavior |
+|--------|-------------|
+| GET/POST | Usually inspected |
+| PUT/PATCH/DELETE | Often not inspected |
+| OPTIONS | Typically bypasses rules |
+
+## WAF Detection Indicators
+
+| Response | Meaning |
+|----------|---------|
+| 403 Forbidden | Request blocked by WAF |
+| 406 Not Acceptable | Content rejected |
+| 429 Too Many Requests | Rate limited |
+| Custom error page | WAF vendor-specific block |
+
+## Python Libraries
+
+| Library | Version | Purpose |
+|---------|---------|---------|
+| `requests` | >=2.28 | HTTP request sending |
+| `urllib.parse` | stdlib | URL encoding/double encoding |
+
+## References
+
+- OWASP WAF Bypass: https://owasp.org/www-community/attacks/WAF_Bypass
+- PortSwigger WAF Bypass: https://portswigger.net/web-security/essential-skills/obfuscating-attacks-using-encodings
+- PayloadsAllTheThings WAF: https://github.com/swisskyrepo/PayloadsAllTheThings/tree/master/WAF%20Bypass