fix(dev-server): improve error page display

[chenjiahan]

Summary

• Enhance error page with status code in title and centered message
• Fix typo in range header variable name

Before

After

Checklist

• Tests updated (or not required).
• Documentation updated (or not required).

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[Copilot]

Pull Request Overview

This PR improves the error page display in the dev server and fixes a typo in a variable name. The main changes include updating the error page HTML to display the status code in the title, center the error message, and add branding, while also correcting the misspelled "rage" variable to "range" in the range header handling.

Key Changes:

• Enhanced error page HTML with status code in title and centered layout
• Fixed variable name typo from "rage" to "range" in range header handling
• Refactored functions to use destructuring for improved readability

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