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/implementing-container-image-minimal-base-with-distroless/references/api-reference.md

@@ -0,0 +1,54 @@
+# API Reference: Distroless Container Image Analysis Agent
+
+## Dependencies
+
+| Library | Version | Purpose |
+|---------|---------|---------|
+| trivy CLI | >=0.50 | Container vulnerability scanning (subprocess) |
+| docker CLI | >=24.0 | Image inspection and property checks (subprocess) |
+
+## CLI Usage
+
+```bash
+python scripts/agent.py \
+  --images gcr.io/distroless/static-debian12 python:3.12-slim \
+  --compare python:3.12 gcr.io/distroless/python3-debian12 \
+  --output-dir /reports/
+```
+
+## Functions
+
+### `run_trivy_scan(image) -> dict`
+Runs `trivy image --format json --severity CRITICAL,HIGH,MEDIUM`.
+
+### `get_image_size(image) -> int`
+Runs `docker inspect --format {{.Size}}` for byte count.
+
+### `count_vulns_by_severity(scan_data) -> dict`
+Parses Trivy JSON Results for CRITICAL/HIGH/MEDIUM/LOW counts.
+
+### `compare_images(base_image, distroless_image) -> dict`
+Scans both images, computes size and vulnerability reduction percentages.
+
+### `check_distroless_properties(image) -> dict`
+Tests for shell access and package manager presence via `docker run`.
+
+### `generate_report(images, distroless_pairs) -> dict`
+Full analysis with individual scans, comparisons, and summary.
+
+## Distroless Properties Checked
+
+| Property | Check Method |
+|----------|-------------|
+| Shell access | `docker run --entrypoint "" image sh -c "echo"` |
+| Package manager | `docker run --entrypoint "" image which apt/apk/yum` |
+
+## Output Schema
+
+```json
+{
+  "summary": {"images_scanned": 4, "minimal_images": 2},
+  "comparisons": [{"size_reduction_pct": 82.3, "vuln_reduction_pct": 95.0}],
+  "image_scans": [{"image": "gcr.io/distroless/static", "is_minimal": true}]
+}
+```