Add error handling to localStorage operations

[vanshika2720]

Summary

This PR adds try-catch blocks to localStorage.setItem() operations across several components to prevent the application from crashing when browser storage is restricted (e.g., in Private Browsing mode or when the storage quota is exceeded).

Fixes #5326

Problem

In many browsers (specifically Safari and Firefox in Private Mode), localStorage read/write operations can throw security exceptions. Additionally, if the disk space is full, it throws a QuotaExceededError. Previously, these were unhandled, causing parts of the UI (theme switching, language switching) to fail silently or crash the script execution.

Solution

Wrapped localStorage.setItem calls in the following files with defensive try-catch blocks:

• [js/themebox.js]
• [js/languagebox.js]
• [js/widgets/reflection.js]

This ensures that even if persistence fails, the application logic continues to run, providing a better user experience through graceful degradation.

Visual Proof

Before Fix

Observation: Attempting to change the theme while storage is blocked results in an uncaught QuotaExceededError at themebox.js:266, stopping the theme from applying.

After Fix

Observation: With the fix, the error is caught at themebox.js:269. The UI remains functional, and a graceful warning is logged to the console instead of a crash.

Checklist

• I have read and followed the project's CONTRIBUTING.md.
• I have tested the changes locally in Safari Private Mode.
• My code follows the project's style guidelines.
• I have provided an AI usage disclosure below.

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[github-actions]

✅ All Jest tests passed! This PR is ready to merge.

[vanshika2720]

Hi @walterbender @vyagh @chimosky
This PR adds defensive try-catch handling around localStorage.setItem() calls to prevent crashes in environments where storage is restricted (such as Safari/Firefox Private Mode or quota limits).

I’ve tested the changes locally (including Safari Private Mode), and the UI now degrades gracefully while logging warnings instead of throwing uncaught exceptions. The implementation follows the existing pattern already used in js/activity.js.

Whenever you have time, I’d appreciate a review. Happy to make any adjustments or improvements if needed — thanks for your time and guidance!

[walterbender]

Looks good but please remove the unrelated PR for abc test.

[github-actions]

❌ Some Jest tests failed. Please check the logs and fix the issues before merging.

Failed Tests:

abc.test.js