Dual-write ENC data into encapi alongside Cobbler

Seed encapi (statuses, roles, prodnxsr node assignments) and make the
instance module also create an encapi_node for every VM, so the k8s
puppetserver ENC can cut over from Cobbler. Cobbler/puppetca/puppetdb
resources are left untouched.

- Add config/encapi leaf + modules/encapi driving statuses/roles/nodes
  from YAML (3 statuses, 51 roles, 13 prodnxsr physical nodes).
- Add encapi_node to modules/instance (certname, role, environment).
- Wire encapi provider into root.hcl required_providers and the module
  providers; plumb ENCAPI_WRITE_TOKEN via Makefile vault_env.

modules/encapi/variables.tf

@@ -0,0 +1,37 @@
+variable "statuses" {
+  description = <<EOT
+Map of encapi statuses (Puppet environments) to seed. Keyed by status name.
+Each value may carry an optional description.
+EOT
+  type = map(object({
+    description = optional(string)
+  }))
+  default = {}
+}
+
+variable "roles" {
+  description = <<EOT
+Map of encapi roles to seed. Keyed by role class name (e.g. roles::base).
+Each value may carry an optional description and a default_params object that
+is jsonencode()'d into the role's inheritable defaults.
+EOT
+  type = map(object({
+    description    = optional(string)
+    default_params = optional(any)
+  }))
+  default = {}
+}
+
+variable "nodes" {
+  description = <<EOT
+Map of encapi node assignments to seed. Keyed by certname. Each value pins the
+node to a role and environment (which must exist as a role/status above), with
+optional per-node params jsonencode()'d into the ENC output.
+EOT
+  type = map(object({
+    role        = string
+    environment = string
+    params      = optional(any)
+  }))
+  default = {}
+}