wasi: a Ctrl-C Interrupt record on guest stdio is treated as a protocol error and closes all three streams #28

Finding (confirmed by reading; live in kore main's composition)

crates/wasi/src/stdio.rs's Shared::receive handles only Data and Closed records. Anything else falls to _ => lost = Protocol (stdio.rs:107). After that, all three guest streams return StreamError::Closed (stdio.rs:296-391), and the receive loop stops (while self.lost.is_none(), stdio.rs:88).

The Interrupt record is legal at any time per kore's process ABI (crates/abi/src/process.rs:166-174, 248-250 in kore). It is sent by:

• the terminal window (crates/stream-host/src/lib.rs:579/617/647);
• the shell's interrupt_child (user/apps/shell/src/main.rs:1579).

User-visible result: Ctrl-C on wasm <guest> ends the guest with stdio lost: Protocol (user/apps/utils/wasm/src/main.rs:299 in kore). It does not deliver an interrupt.

Interaction with the parent's grace: reading the first interrupt record ends the parent's unread-interrupt grace (crates/rt/src/process/interrupt.rs:12-15 in kore). Because later records are never read, a third Ctrl-C, or 60 s after the second, still revokes.

kore main composes exactly this adapter. user/Cargo.toml pins kore-wasi from libkore, and its [patch] maps kore-abi to kore's in-tree ABI, which has carried Interrupt since kore a2866d761 (2026-09-29).

Suggested fix

• Decode Interrupt in receive and record a distinct interrupted state, not Protocol, that keeps any outstanding InputReady.
• Connect that state to the guest's interrupt/cancellation policy, so the host can end the guest cleanly or surface the interrupt to it.
• Add a host test feeding an Interrupt record between Data records.

Surfaced by Copilot's review of #27 (that PR only re-exports native/; this adapter is unchanged there).