test: add more test cases and refactor SelectBestModelForCategory/SelectBestModelFromList/InitializeJailbreakClassifier for testability

[aeft]

What type of PR is this?

test/refactor: add more test cases and refactor SelectBestModelForCategory/SelectBestModelFromList/InitializeJailbreakClassifier for testability

What this PR does / why we need it:

Follow my previous plan to improve the unit tests for the remaining methods in classifier.go
#57

• SelectBestModelForCategory and SelectBestModelFromList contained duplicated and complex logic. I refactored by extracting key methods and added comprehensive test cases
• Refactor InitializeJailbreakClassifier with dependency injection
• Achieving 100% coverage for all main methods: InitializeJailbreakClassifier, CheckForJailbreak, AnalyzeContentForJailbreak, ClassifyCategory, ClassifyPII, DetectPIIInContent, AnalyzeContentForPII, ClassifyAndSelectBestModel, SelectBestModelForCategory, SelectBestModelFromList, GetModelsForCategory.
• Refactor: remove load aware algorithm

Which issue(s) this PR fixes:

Fixes #

Release Notes: No

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[github-actions]

👥 vLLM Semantic Team Notification

The following members have been identified for the changed files in this PR and have been automatically assigned:

📁 config

Owners: @rootfs
Files changed:

• config/config.yaml

📁 deploy

Owners: @rootfs, @Xunzhuo
Files changed:

• deploy/kubernetes/config.yaml

📁 src

Owners: @rootfs, @Xunzhuo, @wangchen615
Files changed:

• src/semantic-router/pkg/config/config.go
• src/semantic-router/pkg/config/config_test.go
• src/semantic-router/pkg/extproc/request_handler.go
• src/semantic-router/pkg/extproc/response_handler.go
• src/semantic-router/pkg/extproc/router.go
• src/semantic-router/pkg/extproc/security_test.go
• src/semantic-router/pkg/extproc/test_utils_test.go
• src/semantic-router/pkg/utils/classification/classifier.go
• src/semantic-router/pkg/utils/classification/classifier_test.go
• src/training/model_eval/result_to_config.py

---

🎉 Thanks for your contributions!

This comment was automatically generated based on the OWNER files in the repository.

[aeft]

@rootfs Updated. I also removed:

• load_aware in the config;
• unused fields (ModelLoad, ModelLoadLock, ModelTTFT) in Classifier;
• return value quality when select models.

[rootfs]

@aeft thanks for contributing!