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/exploiting-idor-vulnerabilities/references/api-reference.md

@@ -0,0 +1,52 @@
+# API Reference: IDOR Vulnerability Testing Agent
+
+## Dependencies
+
+| Library | Version | Purpose |
+|---------|---------|---------|
+| requests | >=2.28 | HTTP client for API endpoint testing |
+
+## CLI Usage
+
+```bash
+python scripts/agent.py \
+  --url https://target.example.com \
+  --token-a "eyJ..." --token-b "eyJ..." \
+  --endpoints "/api/v1/users/{id}/profile" "/api/v1/orders/{id}" \
+  --own-id 101 --other-id 102 \
+  --output idor_report.json
+```
+
+## IDORTester Class
+
+### `__init__(base_url, user_a_token, user_b_token, verify_ssl)`
+Creates two `requests.Session` objects with different Bearer tokens for cross-user testing.
+
+### `test_horizontal_idor(endpoint_template, own_id, other_id, method) -> dict`
+Accesses own resource then another user's resource with the same token. IDOR confirmed when both return 200 with different content.
+
+### `test_vertical_idor(endpoint, method) -> dict`
+Accesses admin-only endpoints with a regular user token. Status 200 indicates missing authorization.
+
+### `test_id_enumeration(endpoint_template, id_range, method) -> dict`
+Iterates over an ID range to discover valid objects. Returns count and sample IDs.
+
+### `test_write_idor(endpoint_template, other_id, payload) -> dict`
+Sends PUT with another user's ID to test write-based IDOR. Status 200/201/204 indicates vulnerability.
+
+### `test_cross_session(endpoint_template, resource_id) -> dict`
+Compares response hashes between two sessions for the same resource to detect missing authorization checks.
+
+### `generate_report() -> dict`
+Returns all accumulated findings with severity assessment.
+
+## Output Schema
+
+```json
+{
+  "target": "https://target.example.com",
+  "total_findings": 2,
+  "findings": [{"type": "horizontal", "endpoint": "/api/v1/users/{id}/profile", "vulnerable": true}],
+  "severity": "High"
+}
+```