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-zero-trust-for-saas-applications/references/api-reference.md

@@ -0,0 +1,47 @@
+# API Reference: Zero Trust for SaaS Applications
+
+## Microsoft Graph API v1.0
+
+### Authentication
+```python
+POST https://login.microsoftonline.com/{tenant}/oauth2/v2.0/token
+Body: grant_type=client_credentials&client_id=X&client_secret=Y&scope=https://graph.microsoft.com/.default
+```
+
+### Conditional Access
+| Method | Endpoint | Description |
+|--------|----------|-------------|
+| GET | `/identity/conditionalAccess/policies` | List CA policies |
+| GET | `/identity/conditionalAccess/policies/{id}` | Get policy details |
+
+### Enterprise Applications
+| Method | Endpoint | Description |
+|--------|----------|-------------|
+| GET | `/servicePrincipals` | List service principals |
+| GET | `/oauth2PermissionGrants` | List OAuth consent grants |
+| GET | `/appRoleAssignments` | List app role assignments |
+
+### Identity Protection
+| Method | Endpoint | Description |
+|--------|----------|-------------|
+| GET | `/identityProtection/riskyUsers` | List at-risk users |
+| GET | `/identityProtection/riskDetections` | Risk detection events |
+
+### CA Policy Grant Controls
+| Control | Description |
+|---------|-------------|
+| `mfa` | Require multi-factor authentication |
+| `compliantDevice` | Require Intune-compliant device |
+| `domainJoinedDevice` | Require hybrid Azure AD join |
+| `passwordChange` | Force password change |
+
+### Risky OAuth Scopes
+| Scope | Risk |
+|-------|------|
+| `Mail.ReadWrite` | Full mailbox access |
+| `Files.ReadWrite.All` | All OneDrive/SharePoint files |
+| `Directory.ReadWrite.All` | Full directory modification |
+
+## References
+- Graph API: https://learn.microsoft.com/en-us/graph/api/overview
+- Conditional Access: https://learn.microsoft.com/en-us/entra/identity/conditional-access/