Document server-sent events support

Merged
KL
4mo ago
+101-0

Documents the server-sent events feature added in #1046.

  • New Server-Sent Events guide (docs/sse.md), added to the nav under Guides. Covers client.sse() for sync and async, POST streaming, the ServerSentEvent fields and .json(), accessing the underlying response, and SSEError.
  • api.md: sse added to the Client / AsyncClient member lists, with new EventSource and ServerSentEvent reference sections.
  • exceptions.md: SSEError added to the hierarchy (under TransportError) and the class listing.

zensical build produces no new warnings.

AI Disclaimer

This PR was developed with the assistance of either Claude or Codex. I've reviewed and verified the changes.