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/implementing-email-sandboxing-with-proofpoint/references/api-reference.md

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+# API Reference: Implementing Email Sandboxing with Proofpoint
+
+## Proofpoint TAP SIEM API
+
+```python
+import requests
+resp = requests.get(
+    "https://tap-api-v2.proofpoint.com/v2/siem/all",
+    auth=(principal, secret),
+    params={"sinceSeconds": 3600, "format": "json"})
+data = resp.json()
+# Keys: messagesDelivered, messagesBlocked, clicksPermitted, clicksBlocked
+```
+
+## TAP API Endpoints
+
+| Endpoint | Description |
+|----------|-------------|
+| `/v2/siem/all` | All threat events |
+| `/v2/siem/messages/blocked` | Blocked messages only |
+| `/v2/siem/messages/delivered` | Delivered threats |
+| `/v2/siem/clicks/blocked` | Blocked URL clicks |
+| `/v2/siem/clicks/permitted` | Permitted URL clicks |
+
+## Threat Categories
+
+| Category | Description | Severity |
+|----------|-------------|----------|
+| Malware | Malicious attachment | CRITICAL |
+| Phish | Credential harvesting | HIGH |
+| Impostor | BEC/spoofing | HIGH |
+| Spam | Unsolicited | LOW |
+
+## URL Defense Configuration
+
+```json
+{
+  "url_defense": {
+    "rewrite_all_urls": true,
+    "real_time_scanning": true,
+    "sandbox_detonation": true,
+    "click_time_protection": true
+  }
+}
+```
+
+## Splunk Integration
+
+```spl
+index=proofpoint sourcetype=tap:siem
+| where classification="malicious"
+| stats count by sender, threatType, subject
+```
+
+### References
+
+- Proofpoint TAP API: https://help.proofpoint.com/Threat_Insight_Dashboard/API_Documentation
+- Proofpoint Email Protection: https://www.proofpoint.com/us/products/email-security-and-protection