Request and response examples for API endpoints

REST and GraphQL API consumers can't integrate correctly without knowing exactly what to send and what to expect back. Documentation that describes an endpoint without showing an example request and response forces developers to guess at header formats, body structure, and response shapes — every guess is a potential bug. OpenAPI specs with 'string' placeholders for every field value are no better than no docs at all: they show structure but not semantics, valid values, or what realistic data looks like. iso-25010:2011 analysability requires that a system be understandable without probing it experimentally.

For each endpoint, show a complete curl request and the matching response with realistic (not placeholder) field values:

### POST /api/users

**Request:**
```bash
curl -X POST https://api.example.com/api/users \
  -H "Authorization: Bearer sk-..." \
  -H "Content-Type: application/json" \
  -d '{"name": "Jane Smith", "email": "jane@example.com"}'

Response (201):

{
  "id": "usr_abc123",
  "name": "Jane Smith",
  "email": "jane@example.com",
  "created_at": "2026-03-29T12:00:00Z"
}

Never use 'string' or 'value' as example field values — use realistic data that shows the actual format consumers will receive.