- buildBaseUrl treated any host starting with 'http' (e.g. httpbin.local) as having a scheme
- native streaming finished silently on 4xx/5xx; it now reports the status
- network failures now explain how to fix the connection instead of 'XHR streaming failed: 0'
- testConnection left its 5 s timer running on failure
- SSE parser accepts 'data:' without a space, as the spec allows
evandro