Add garbled detection tests.

[shun8686]

Motivation

Modifications

Accuracy Tests

Speed Tests and Profiling

Checklist

• Format your code according to the Format code with pre-commit.
• Add unit tests according to the Run and add unit tests.
• Update documentation according to Write documentations.
• Provide accuracy and speed benchmark results according to Test the accuracy and Benchmark the speed.
• Follow the SGLang code style guidance.

Review and Merge Process

1. Ping Merge Oncalls to start the process. See the PR Merge Process.
2. Get approvals from CODEOWNERS and other reviewers.
3. Trigger CI tests with comments or contact authorized users to do so.
   • Common commands include /tag-and-rerun-ci, /tag-run-ci-label, /rerun-failed-ci
4. After green CI and required approvals, ask Merge Oncalls or people with Write permission to merge the PR.

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CI States

Latest PR Test (Base): ❌ Missing run-ci label -- add it to run CI tests.
Latest PR Test (Extra): ❌ Blocked -- run-ci is required first.

[ascend-robot]

CLA Signature Guide

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[ascend-robot]

CLA Signature Guide

@shun8686 , thanks for your pull request.

The following commit(s) are not associated with a signed Contributor License Agreement (CLA).

Commit	Reason
5061602e Add garbled detection utils.	the email used in the commit is not linked to a signed CLA! please verify that it matches the email you used when signing the CLA.

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To check if your email is configured correctly, refer to the FAQs.

Once you've signed the CLA or updating your email, please comment /check-cla to revalidate CLA status.