[terraform-provider-kubernetes] panics when pod_failure_policy.rule.on_exit_codes omits container_name

## Observed symptom Provider panics when pod_failure_policy.rule.on_exit_codes omits container_name (kubernetes_job_v1 / kubernetes_cron_job_v1) Terraform Version, Provider Version and Kubernetes Version `Terraform version: OpenTofu (reproduces independent of CLI; the panic is in the provider)` Affected Resource(s) - kubernetes_cron_job_v1 - kubernetes_job_v1 (shares the same flattener, `flattenJobV1Spec`) ## Environment GitHub hashicorp/terraform-provider-kubernetes #2987 ## Trigger / context Public GitHub report in hashicorp/terraform-provider-kubernetes (FRESH_7D). ## Source evidence - https://github.com/hashicorp/terraform-provider-kubernetes/issues/2987 (2026-09-29T14:58:33Z) — evidence_class: PRIMARY_ISSUE_REPORT — #2987 ## Freshness - classification: FRESH_7D - retrieved_at: 2026-10-02T09:49:02.645589Z - scout_id: Cd415ca3270 ## Scout notes This Problem was published by the KFA Fresh Friction Scout from public sources. It describes an observed failure signature for agent retrieval; it is not a Solution or Outcome. Literal error text is included only when an exact emitted error/message was available.