feat(observability): file logging, crash handlers, per-run script logs, toast queue

[thisiscsim]

Summary

Audit roadmap Phase 5 (observability foundation). Before this, the main process logged nothing, had no crash/rejection handlers, and engine-script stdout/stderr was parsed then discarded — when something broke, a user could send us a screenshot of an 8-second toast and nothing else. This is also Stage 1 of the debug-console recommendation: the logging/version substrate a report bundle or command palette would build on.

Main process

• logger.ts: leveled file logger at userData/logs/main.log (rotated at 2 MB, one backup), mirrored to the dev console.
• installCrashHandlers() for uncaughtException/unhandledRejection; render-process-gone + unresponsive logged on the window.
• runScriptArgs tees each script run's full stdout+stderr to userData/logs/scripts/<prefix>-<ts>.log and logs start/exit.
• app:info IPC (version / electron / chrome / node / platform / logsDir) so a report can be correlated to a build; log:renderer IPC.

Renderer

• window.onerror / onunhandledrejection and the ErrorBoundary now persist to the shared log via log:renderer (previously only a usually-closed DevTools console saw them).
• Toast is now a queue (notices[]): concurrent operations no longer overwrite each other's messages; errors persist until dismissed (close button, role="alert") while info auto-dismisses. Fixes the bug where the dismiss timer restarted on every App re-render (so an error toast shown mid-edit never cleared) by keying per notice id.
• Replaced the raw #c0392b toast hex with --foreground-danger (token).

Main-process + preload change — restart npm run dev.

Test plan

• Store autosave-failure test updated for the queue; 101 tests green
• typecheck / lint / format / build green
• Manual (post-merge): trigger a failed generate → error toast persists with a close button + a line in userData/logs/scripts/…; main.log records startup + script runs

Made with Cursor