Server (sx_server.ml):
- eval_with_io: CEK evaluator with IO suspension handling (io-sleep, import)
- io-sleep platform primitive: raises CekPerformRequest, resolved by eval_with_io
- Streaming render uses eval_with_io for data + content evaluation
- Data items with "delay" field sleep before resolving (async streaming)
- Removed hardcoded streaming-demo-data — application logic belongs in .sx
Application (streaming-demo.sx):
- streaming-demo-data defined in SX: 3 items with 1s/3s/5s delays
- Each item has delay, stream-id, and display data fields
- Shell renders instantly, slots fill progressively as IO completes
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>