Replace plain TCP JSON-lines connections with bounded loopback WebSockets using the required runa-debug subprotocol. Keep single-threaded image dispatch and stdio framing unchanged.
Broadcast coalesced, non-destructive image_changed invalidations after successful mutations. Update the REPL client and automatically refresh VS Code actor trees and open inspectors, preserving request correlation and connection-session isolation.
Validate negotiation, message limits and fragmentation, multi-client notifications, real REPL interoperability, and automatic mailbox/lifecycle/failure inspection in a VS Code extension host.
BREAKING CHANGE: the network endpoint now accepts only runa-debug WebSockets at the root path, not plain TCP JSON Lines. Rust network integrations must use WebSocketClient and serve_websocket. Request/response DTOs remain protocol v3; stdio is unchanged.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
