Bugfix/updating as per guideline

[02karthik]

What is this tool?

Checklist

• It's a single file: <slug>/index.html with all CSS + JS inline.
• It is fully self-contained / offline — no remote fonts, scripts,
  styles, images, fetch, or import (the app blocks the network via CSP).
• No analytics, trackers, or phone-home behavior.
• Added a screenshot at screenshots/<slug>.webp (via npm run screenshot <slug>).
• Registered the tool in tools.json (dir matches the folder name).
• Bumped the top-level catalogVersion.
• For an update to an existing tool: incremented that tool's version.
• npm run validate passes locally.

Notes for reviewers