Rate limits

Two separate buckets per API key:

• public-write: 60 requests/min — all POST /v1/presentations/* endpoints

• public-read: 600 requests/min — GET /v1/presentations/{id}

Every response includes x-ratelimit-limit, x-ratelimit-remaining, and x-ratelimit-reset (milliseconds until the window resets). Exceeding a bucket returns 429 RATE_LIMIT_EXCEEDED.