Add Agent Passport System to Identity & Authentication

[aeoess]

Adds Agent Passport System to the Identity & Authentication section.

APS is an open protocol for AI agent identity, scoped delegation, and enforcement:

• Ed25519 cryptographic identity with passport grades (0-3)
• Delegation chains with monotonic narrowing (authority can only decrease)
• 3-signature action chain: intent → policy evaluation → execution receipt
• 4-gate commerce authorization: passport, scope, spend limit, merchant allowlist
• Cascade revocation — revoking parent invalidates all children
• Values Floor governance with 7 attested principles
• Merkle-committed settlements for tamper-evident audit trails
• GDPR Art. 30 / EU AI Act Art. 10 compliance evidence export

103 modules, 2,000+ tests. Apache-2.0.

Available on npm (agent-passport-system), PyPI (agent-passport-system), and as an MCP server (agent-passport-system-mcp).

Referenced in OWASP Agentic Top 10 threads (#802, #812, #817), A2A protocol discussions, and Microsoft AGT (merged PR #598).