[DID-104] documentation: Create API reference for all PoP endpoints

[umwelt]

Overview

Create comprehensive API documentation for all Proof of Personhood endpoints.

Acceptance Criteria

• Document all endpoints:
  • Staking (POST /stake/citizenship, GET /stake/status)
  • Vouching (POST /identity/vouch, GET /identity/vouchers)
  • Biometric (POST /identity/biometric/verify, GET /identity/biometric/status)
  • UBI (GET /ubi/status, GET /ubi/treasury/status)
  • Access (POST /dao//access//issue)
  • Swap (POST /swap/execute)
• Request/response examples
• Error codes and descriptions
• Rate limiting information
• Authentication requirements
• Pagination documentation

Sections per Endpoint

• Purpose and use case
• Request format (JSON schema)
• Response format (JSON schema)
• Example requests/responses
• Error handling
• Rate limits

Files to Modify

• docs/API/PoP_ENDPOINTS.md (new)

Phase

Phase 5 - Documentation & Migration