fix(chart): disable model cache when modelCache.enabled is false

[eleboucher]

Problem

Setting modelCache.enabled: false does not actually disable the model cache. The operator's --model-cache-path flag defaults to /models (cmd/main.go), and caching is gated on that path being non-empty:

• internal/controller/inferenceservice_controller.go: model.Status.CacheKey != "" && r.ModelCachePath != ""
• internal/controller/deployment_builder.go: useCache := model.Status.CacheKey != "" && r.ModelCachePath != ""

The chart only emits the --model-cache-* flags when enabled: true, so when disabled the operator falls back to the non-empty /models default and keeps provisioning + mounting the cache (a shared 100Gi PVC) anyway.

Fix

Emit an explicit empty --model-cache-path= in the disabled branch so the controller's path != "" gate evaluates false and caching is actually off.

Test

Added a helm-unittest regression case to tests/model-cache_test.yaml asserting that with modelCache.enabled: false the deployment passes --model-cache-path= (empty), no --model-cache-path=/models, and no /models volume mount. Full suite passes (10/10).

[eleboucher]

Btw you shouldn't put the github actions to run unless you approve it, to prevent from cache poisoning and attacker getting your secrets

[Defilan]

Thanks for this contribution! Good callout with actions. I set up the initial policy when the project was smaller that I had to approve actions for new contributors but allow it for returning ones. Now that the project has grown, it's worth revisiting that. Appreciate your callout on this.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

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