Worker's uncaughtException and unhandledRejection handlers are empty, so worker crashes leave no trace

Description

Both process-level handlers in packages/opencode/src/cli/tui/worker.ts are empty functions:

const onUnhandledRejection = (_error: unknown) => {}

const onUncaughtException = (_error: Error) => {}

process.on("unhandledRejection", onUnhandledRejection)
process.on("uncaughtException", onUncaughtException)

Registering a handler suppresses Node's default behaviour — print the stack, exit non-zero — so an empty one turns a worker crash into silence. Nothing is written to the log, and the TUI keeps talking to a worker that may be gone.

#42885 covers the RPC path (a throwing handler, a killed worker), but it doesn't touch these two handlers, so a failure that never crosses the RPC boundary stays invisible.

Logging the error before returning would be enough — synchronously, since the process may be about to exit. In a build where the handler does that, the one crash it caught over several weeks was Error: EIO: i/o error, write, which is otherwise lost entirely.

Happy to open a PR if that's welcome.

Steps to reproduce

1. In packages/opencode/src/cli/tui/worker.ts, add setTimeout(() => { throw new Error("boom") }, 4000) before the process.on calls.
2. Run bun dev .
3. After 4 seconds: the TUI is still up, boom appears nowhere — not on stdout, not in the log directory.

OpenCode version

1.18.27

Operating System

Ubuntu 24.04 (WSL2)

Terminal

Ubuntu-24.04