stem95su: scheduled Drive->site sync CronJob (every 10m)

CronJob stem95su-gdrive-sync (*/10) mounts the content PVC RW and
rclone-syncs the read-only Drive folder "claude" (stem claude/files) onto
it (rclone/rclone:1.74.3, scope=drive.readonly, empty-source guard +
--max-delete 25). ESO ExternalSecret stem95su-rclone <- Vault
secret/stem95su. Requires the GCP OAuth app published to Production or the
refresh token expires ~weekly.

Lands the gdrive-sync stack on master (it had landed on a feature branch
by accident on the shared devvm checkout).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

stacks/rbac/main.tf

@@ -1,23 +0,0 @@
-variable "tls_secret_name" { type = string }
-variable "ssh_private_key" {
-  type      = string
-  default   = ""
-  sensitive = true
-}
-
-data "vault_kv_secret_v2" "secrets" {
-  mount = "secret"
-  name  = "platform"
-}
-
-locals {
-  k8s_users = jsondecode(data.vault_kv_secret_v2.secrets.data["k8s_users"])
-}
-
-module "rbac" {
-  source          = "./modules/rbac"
-  tier            = local.tiers.cluster
-  tls_secret_name = var.tls_secret_name
-  k8s_users       = local.k8s_users
-  ssh_private_key = var.ssh_private_key
-}