Cancellation inside `send_all()` can publish a partial frame. Closing
the actor-wide stream preserved framing but destroyed every context
on the channel and replaced primary errors with `TransportClosed`.
Deats,
- shield complete frame publication, then deliver pending
cancellation
- keep the shared channel reusable after context-local cancellation
- absorb transport closure while reporting an unshippable overrun
- cover mid-frame cancellation and failed overrun error shipment
This deliberately defers cancellation until the current frame write
resolves; channel teardown remains the fallback for broken peers.
Prompt-IO: ai/prompt-io/opencode/20260819T234824Z_557065d8_prompt_io.md
(this patch was generated in some part by `opencode` using `gpt-5.6-sol` (`openai`))
Gud Boi
643e1c861b