Electron's console-message event only surfaces {level, message, line, sourceId}
without the stack, so uncaught errors showed up as 'line 1028 of chunk-*.js'
(SolidJS's rethrow site) with no way to find the real origin. Attach
window error and unhandledrejection listeners that log the full stack via
console.error, and reshape the main-process log line so newlines in the
stack survive instead of being JSON-escaped into one unreadable blob.