TektonConfig auto-install fails when the webhook service is not named tekton-operator-webhook (kodata hardcodes service.name; WEBHOOK_SERVICE_NAME env is ignored for clientConfig)

Related: #624 (closed in 2022 — reopening the case since the Helm chart makes non-default service names common).

What happened: Installing the operator with any service name other than tekton-operator-webhook leaves the operator and webhook pods healthy, but TektonConfig auto-install fails:

Failed to create TektonConfig instance ... failed calling webhook "webhook.operator.tekton.dev":
Post "https://tekton-operator-webhook.tekton-operator.svc:443/defaulting?timeout=10s":
service "tekton-operator-webhook" not found   (pkg/reconciler/shared/tektonconfig/instance.go:91)

Repro (verified on kind v1.34.0 with the v0.81.1 chart, any release name ≠ tekton-operator): helm install to charts/tekton-operator … → the webhook service is to-tekton-operator-webhook, but the MutatingWebhookConfiguration registered by the webhook binary points at the literal tekton-operator-webhook.

Root cause: cmd/{kubernetes,openshift}/webhook/kodata/validating-defaulting-webhook/500-webhooks.yaml pins service.name: tekton-operator-webhook. The WEBHOOK_SERVICE_NAME env var (cmd/*/webhook/main.go) flows into kwebhook.Options but only affects cert rotation and leader election — the kodata clientConfig is applied as-is.

Fix directions: rewrite the kodata webhook configs' clientConfig (service name + namespace) from Options.ServiceName/system namespace before applying; or document that the service must keep the default name.

Full verification details in the evidence comment on #3945.

Start with cmd/{kubernetes,openshift}/webhook/kodata/validating-defaulting-webhook/500-webhooks.yaml and trace WEBHOOK_SERVICE_NAME from cmd/*/webhook/main.go into kwebhook.Options. Check how the kodata clientConfig is applied during webhook setup. Done means a non-default Helm release name produces a MutatingWebhookConfiguration targeting the actual webhook service and TektonConfig auto-install succeeds.