[daggerok]

What

• Settings useState initializer: localStorage.getItem moved inside the existing try, falls back to DEFAULT_SETTINGS
• Settings sync effect: localStorage.setItem wrapped in try/catch with a console.warn; the theme class is applied either way

Why

CSV-M1: these were the only two unguarded storage calls (NEEDS_BOOT_RESTORE and the dataset helpers already catch). When storage is blocked, getItem throws SecurityError during the first render and the app shows a blank page. With a full quota, setItem throws inside the effect, so dark or light mode is not applied. Split from the parser fix to keep one concern per PR

Checks

• bun run build
• tsc --noEmit --strict --skipLibCheck --jsx react-jsx on src/main.tsx (no errors)
• Old and new initializer and effect extracted from source and run in Bun with stub storages:
  • blocked storage: old initializer throws SecurityError, new returns defaults; old effect throws, new applies dark
  • full quota on setItem: old effect throws QuotaExceededError, new applies dark
  • saved settings and broken JSON behave as before
• git diff --check
• Not run in a browser