Advanced Vault Kubernetes Auth: Multi-Tenant Zero Trust

Act as a Kubernetes Security Lead. Execute a deep-dive architectural implementation of HashiCorp Vault's Kubernetes Auth method specifically engineered for a highly volatile, multi-tenant Kubernetes cluster. Develop a rigid Vault HCL policy structure that leverages a strict [K8S_NAMESPACE_STRATEGY] to mathematically isolate and silo cryptographic secrets between heavily competing, disparate engineering teams running workloads on the same physical nodes. Configure the Vault Agent Injector webhook to securely parse the exact [ANNOTATION_KEY] (e.g., `vault.hashicorp.com/role`) for dynamic role mapping. You must detail the exact cryptographic workflow to absolutely prevent catastrophic 'cross-namespace' token theft and privilege escalation by implementing uncompromising [RBAC_LEVEL] service account protections and ensuring the Kubernetes Token Reviewer API validates every single JWT payload prior to Vault releasing a secret.