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/testing-for-email-header-injection/references/api-reference.md

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+# API Reference: Testing for Email Header Injection
+
+## CRLF Encoding Variants
+
+| Encoding | Representation | Description |
+|----------|---------------|-------------|
+| `%0A` | LF | URL-encoded line feed |
+| `%0D%0A` | CRLF | URL-encoded carriage return + line feed |
+| `%0D` | CR | URL-encoded carriage return |
+| `%250A` | Double-encoded LF | Bypasses single decode |
+| `\n` | Raw LF | Direct newline character |
+
+## Injectable Headers
+
+| Header | Impact | Severity |
+|--------|--------|----------|
+| Cc: | Send copy to attacker | High |
+| Bcc: | Hidden copy to attacker | High |
+| From: | Email spoofing | Medium |
+| Reply-To: | Phishing redirect | Medium |
+| Subject: | Subject override | Low |
+| Content-Type: | Body injection | High |
+| To: | Additional recipients | High |
+
+## Common Injection Points
+
+| Endpoint | Field | Risk |
+|----------|-------|------|
+| /contact | email, name, subject | Header injection |
+| /share | to, from | Recipient injection |
+| /invite | email | Mass invitation abuse |
+| /forgot-password | email | CC token to attacker |
+| /api/send-email | to, subject, body | Full control |
+
+## Attack Scenarios
+
+| Scenario | Technique |
+|----------|-----------|
+| Spam relay | Inject BCC with mass recipients |
+| Phishing | Override From/Reply-To |
+| Password reset hijack | CC reset token email |
+| Content override | MIME boundary injection |
+
+## Python Libraries
+
+| Library | Version | Purpose |
+|---------|---------|---------|
+| `requests` | >=2.28 | HTTP form submission |
+| `json` | stdlib | Report generation |
+
+## References
+
+- OWASP Email Injection: https://owasp.org/www-community/attacks/Email_Injection
+- swaks SMTP testing: https://www.jetmore.org/john/code/swaks/
+- mailhog: https://github.com/mailhog/MailHog