react-zmage error recovery

Non-existent zmage.caldis.me paths may return a GitHub Pages HTML 404. That is a static documentation miss, not a failed product API call.

Recovery order

Fetch /llms.txt for the compact integration contract, /llms-full.txt for the full single-file context, /index.md for a markdown homepage, npm for package metadata, and GitHub for source code.

Structured future shape

If react-zmage ever adds a hosted API, error responses should use JSON with error, code, message, and retry_after fields. Today there is no hosted API returning JSON errors.