fix: increase error overlay z-index

[yue1123]

Description

In some cases, error-overlay is blocked by other higher z-index elements, as follows:

Additional context

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What is the purpose of this pull request?

• Bug fix
• New Feature
• Other
• Documentation update

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• Read the Contributing Guidelines.
• Read the Pull Request Guidelines and follow the Commit Convention.
• Check that there isn't already a PR that solves the problem the same way to avoid creating a duplicate.
• Provide a description in this PR that addresses what the PR is solving, or reference the issue that it solves (e.g. fixes #123).
• Ideally, include relevant tests that fail without this PR but pass with it.