TERRAFORM - Replace AGIC with Application Gateway for Containers (AGC) + Gateway API #174
Description
Retire the legacy AGIC ingress controller and migrate to Application Gateway for Containers integrated with the Gateway API. This enables modern ingress features, elasticity, and simplified L7 policy management.
• Deploy AGC controller Helm release (e.g., azurerm_kubernetes_cluster_extension or Helm provider).
• Add subnet delegation for AGC in network module.
• Replace Ingress YAML with Gateway/HTTPRoute resources.