Add terraform-enc auth, consul state role, and encapi token grant

The new terragrunt-enc repo manages all encapi ENC data via Terraform and
needs its own Vault/Consul plumbing, mirroring terraform-git/terraform-incus:
CI auth, isolated consul state, and read access to the ENCAPI_WRITE_TOKEN.

- Add approle role terraform_enc and k8s auth role woodpecker_terraform_enc
  (bound to the terraform-enc SA in the woodpecker namespace).
- Add consul secret backend role + ACL rules granting write on
  infra/terraform/enc/ for its terragrunt state, plus a policy letting both
  auth roles read consul_root/au/syd1/creds/terraform-enc.
- Grant both auth roles read on
  kv/data/kubernetes/namespace/encapi/default/environment (ENCAPI_WRITE_TOKEN).

config/auth_approle_role/approle/terraform_enc.yaml

@@ -0,0 +1,9 @@
+token_ttl: 120
+token_max_ttl: 120
+bind_secret_id: false
+token_bound_cidrs:
+  - "10.10.12.200/32"
+  - "198.18.25.102/32"
+  - "198.18.26.91/32"
+  - "198.18.27.40/32"
+use_deterministic_role_id: true

config/auth_kubernetes_role/k8s/au/syd1/woodpecker_terraform_enc.yaml

@@ -0,0 +1,7 @@
+bound_service_account_names:
+  - terraform-enc
+bound_service_account_namespaces:
+  - woodpecker
+token_ttl: 600
+token_max_ttl: 600
+audience: https://kubernetes.default.svc.cluster.local

config/consul_secret_backend_role/consul_root/au/syd1/terraform-enc.yaml

@@ -0,0 +1,5 @@
+consul_roles:
+  - terraform-enc
+ttl: 120
+max_ttl: 300
+datacenters: []

policies/consul_root/au/syd1/creds/terraform-enc.yaml

@@ -0,0 +1,14 @@
+# Allow the terragrunt-enc runner to generate credentials for the
+# terraform-enc role in consul (used to lock/write its terragrunt state under
+# infra/terraform/enc/ on the consul backend).
+---
+rules:
+  - path: "consul_root/au/syd1/creds/terraform-enc"
+    capabilities:
+      - read
+
+auth:
+  approle:
+    - terraform_enc
+  k8s/au/syd1:
+    - woodpecker_terraform_enc

policies/kv/service/terraform/enc-encapi-environment.yaml

@@ -0,0 +1,14 @@
+# Allow the terragrunt-enc runner to read the encapi environment secret
+# (ENCAPI_WRITE_TOKEN), so `make apply` can write ENC data (statuses, roles,
+# nodes) to encapi via the encapi Terraform provider.
+---
+rules:
+  - path: "kv/data/kubernetes/namespace/encapi/default/environment"
+    capabilities:
+      - read
+
+auth:
+  approle:
+    - terraform_enc
+  k8s/au/syd1:
+    - woodpecker_terraform_enc

resources/secret_backend/consul_root/au/syd1/terraform-enc.hcl

@@ -0,0 +1,7 @@
+key_prefix "infra/terraform/enc/" {
+  policy = "write"
+}
+
+session_prefix "" {
+  policy = "write"
+}