Code review response: Frontend code quality and architectural analysis

[Copilot]

Performed comprehensive frontend code review as requested, covering entire codebase in fitch-proof/packages/app/.

Review Scope

• Code Quality: TypeScript type safety, error handling, memory management, code organization
• Architecture: State management patterns, event handling, module structure
• Security: XSS vectors, data validation, storage security
• Performance: Keystroke-triggered operations, bundle size, DOM manipulation
• Accessibility: ARIA labels, keyboard navigation, screen reader support, WCAG compliance
• UX: Dark mode persistence, responsive design, error messaging

Key Findings

Critical:

• Autosave runs on every keystroke without debouncing (lines 552-555 in main.ts)
• Missing error handling for localStorage operations - invalid JSON crashes app
• innerHTML usage without sanitization (line 389)
• Multiple @ts-ignore suppressions masking type errors

Structural:

• main.ts at 620 lines needs decomposition into focused modules
• Memory leaks from undisposed Monaco models and event listeners
• Race conditions in tab management and localStorage synchronization
• TypeScript strict mode disabled, pervasive implicit any types

Accessibility:

• Missing lang attribute, ARIA labels, keyboard navigation patterns
• Color contrast issues in syntax highlighting themes
• No screen reader support for proof feedback

No code changes required - this PR documents the review findings for discussion.

---

✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.