Complete folder anatomy for all 649 cybersecurity skills + update LICENSE to Mahipal

- Add scripts/agent.py and references/api-reference.md to all remaining skills
- Update all 648 LICENSE files: copyright now reads 'Mahipal'
- Add implementing-security-monitoring-with-datadog (new skill with full anatomy)
- All 649 skills now have: SKILL.md, LICENSE, scripts/agent.py, references/api-reference.md

skills/performing-api-rate-limiting-bypass/references/api-reference.md

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+# API Rate Limiting Bypass — API Reference
+
+## Libraries
+
+| Library | Install | Purpose |
+|---------|---------|---------|
+| requests | `pip install requests` | HTTP request sending with custom headers |
+
+## Rate Limit Response Headers
+
+| Header | Description |
+|--------|-------------|
+| `X-RateLimit-Limit` | Maximum requests per window |
+| `X-RateLimit-Remaining` | Requests remaining in window |
+| `X-RateLimit-Reset` | Timestamp when limit resets |
+| `Retry-After` | Seconds to wait before retrying |
+| `RateLimit-Policy` | IETF draft rate limit policy |
+
+## IP Spoofing Bypass Headers
+
+| Header | Description |
+|--------|-------------|
+| `X-Forwarded-For` | Standard proxy forwarding header |
+| `X-Real-IP` | NGINX real client IP |
+| `X-Originating-IP` | Client originating IP |
+| `X-Client-IP` | Client IP identifier |
+| `True-Client-IP` | Akamai/CDN client IP |
+| `CF-Connecting-IP` | Cloudflare client IP |
+| `Forwarded` | RFC 7239 forwarded header |
+
+## Bypass Techniques
+
+| Technique | Description | Severity |
+|-----------|-------------|----------|
+| Header IP rotation | Rotate X-Forwarded-For per request | HIGH |
+| HTTP method switching | GET rate-limited but POST is not | MEDIUM |
+| Path variation | `/api/users` vs `/api/users/` | MEDIUM |
+| Case variation | `/API/Users` vs `/api/users` | MEDIUM |
+| URL encoding | `%2Fapi%2Fusers` instead of `/api/users` | MEDIUM |
+| Null byte injection | Append `%00` to URL path | HIGH |
+| API version switching | `/v1/users` vs `/v2/users` | MEDIUM |
+| Parameter pollution | Duplicate query parameters | MEDIUM |
+
+## OWASP API4:2023 — Unrestricted Resource Consumption
+
+| Risk | Description |
+|------|-------------|
+| Missing rate limits | No throttling on sensitive endpoints |
+| Per-IP only limits | Bypassed with header spoofing |
+| No auth-based limiting | Rate limit tied to IP, not user |
+| Inconsistent enforcement | Different limits per method/version |
+
+## External References
+
+- [OWASP API Security Top 10](https://owasp.org/API-Security/)
+- [IETF RateLimit Header Fields](https://datatracker.ietf.org/doc/draft-ietf-httpapi-ratelimit-headers/)
+- [HackTricks Rate Limit Bypass](https://book.hacktricks.xyz/pentesting-web/rate-limit-bypass)