fix(serving): re-create a missing well-known LLMInferenceServiceConfig

[teemow]

Towards #508

Problem

The kserve-runtime-configs HelmRelease carries no drift detection, so helm-controller judges it by its Helm storage alone. When the well-known LLMInferenceServiceConfigs disappear from the cluster (a slice torn down at once left them terminating under the llm-d controller's finalizer, the next install adopted them and the new controller finished their deletion), the release stays "in-sync" with no config behind it, and every LLMInferenceService composed from them fails PresetsCombined=False ConfigNotFound until a forced reconcile.

Change

• components.kserve-runtime-configs.driftDetection.mode: enabled is the default in values.yaml, forwarded verbatim into the child HelmRelease's spec.driftDetection by templates/components.yaml. On every reconcile (gitops.interval) helm-controller re-applies a missing or changed config as a server-side apply, without a Helm revision.
• No ignore rule: the configs are configuration only, the controller's finalizer survives a server-side apply of the manifest, and no webhook mutates them. The other serving releases keep helm-controller's default.
• examples/serving-slice.yaml shows the setting; CHANGELOG entry; README and values.schema.json regenerated; the comments that named the set of drift-detecting releases name the third.
• Tests: tests/verify-serving-slice.py asserts spec.driftDetection.mode: enabled on the slice's kserve-runtime-configs release and none on its other releases (a render without the default fails naming the release); tests/verify-kagent-wiring.py adds it to the set of releases that carry drift detection.

Proof

• Local: make verify-serving-slice, make verify-meta, make verify-target pass; pre-commit on the changed files passes. A render without the default fails verify-serving-slice naming the release.
• CI: green on 54e6999.
• Live, a local kind lab with the serving slice on and this checkout's chart (CRs only, no GPU):
  • The kserve-runtime-configs HelmRelease carries spec.driftDetection: {mode: enabled}, and only kagent, muster and this release carry drift detection.
  • In sync: two requested reconciles log release in-sync with desired state. The configs carry serving.kserve.io/llmisvcconfig-finalizer, so the controller's finalizer is not reported as drift.
  • KServe's validating webhook refuses a direct delete (well-known config agent-platform/kserve-config-llm-tracing cannot be deleted). To delete one by hand, its DELETE operation was lifted and restored straight after the delete; the config was gone at 16:34:08Z.
  • On the release's next scheduled reconcile (10m interval, nothing requested, no --force) helm-controller logged detected changes in cluster state: removed: 1 and correct cluster drift, emitted DriftDetected and DriftCorrected, and re-created the config at 16:43:23Z (new uid, the controller's finalizer back on it). The webhook admitted the CREATE, and all ten configs were present.
  • Helm revision unchanged (v8). A following requested reconcile logs release in-sync with desired state with Drifted=False, so there is no perpetual drift. One benign Drifted condition patch conflict was logged and resolved on the immediate requeue.

[circleci-architect]

Published Helm chart agent-platform-connectivity

4.67.1-r9d846806t20260924154737h54e6999

Chart	agent-platform-connectivity
Version	4.67.1-r9d846806t20260924154737h54e6999
OCI reference	oci://gsoci.azurecr.io/charts/giantswarm/agent-platform-connectivity:4.67.1-r9d846806t20260924154737h54e6999
Digest	sha256:faed62a452af02d2994a0a7e59509de50ed013a37dc44a2b064f584d253cde81
Registry	public — gsoci.azurecr.io
Git catalog	giantswarm-test-catalog (index)

Pull this chart

helm pull oci://gsoci.azurecr.io/charts/giantswarm/agent-platform-connectivity --version 4.67.1-r9d846806t20260924154737h54e6999

_{Posted by architect-orb · build 12777 · commit 54e6999 · updated in place on every push}

[circleci-architect]

Published Helm chart agent-platform

4.67.1-r9d846806t20260924154737h54e6999

Chart	agent-platform
Version	4.67.1-r9d846806t20260924154737h54e6999
OCI reference	oci://gsoci.azurecr.io/charts/giantswarm/agent-platform:4.67.1-r9d846806t20260924154737h54e6999
Digest	sha256:b2c2f06a819bf18a65db52b527d009cc2b7b9a4379ba7176c9dd252c4c05a975
Registry	public — gsoci.azurecr.io
Git catalog	giantswarm-test-catalog (index)

Pull this chart

helm pull oci://gsoci.azurecr.io/charts/giantswarm/agent-platform --version 4.67.1-r9d846806t20260924154737h54e6999

_{Posted by architect-orb · build 12774 · commit 54e6999 · updated in place on every push}