migrate 16 plan-time stacks: vault data source → ESO + kubernetes_secret

Replaced data "vault_kv_secret_v2" with:
1. ExternalSecret (ESO syncs Vault KV → K8s Secret)
2. data "kubernetes_secret" (reads ESO-created secret at plan time)

This removes the Vault provider dependency at plan time for these
stacks — they now only need K8s API access, not a Vault token.

Stacks: actualbudget, affine, audiobookshelf, calibre, changedetection,
coturn, freedify, freshrss, grampsweb, navidrome, novelapp, ollama,
owntracks, real-estate-crawler, servarr, ytdlp

stacks/changedetection/main.tf

@@ -3,16 +3,6 @@ variable "tls_secret_name" {
   sensitive = true
 }
 variable "nfs_server" { type = string }
-data "vault_kv_secret_v2" "secrets" {
-  mount = "secret"
-  name  = "changedetection"
-}
-
-locals {
-  homepage_credentials = jsondecode(data.vault_kv_secret_v2.secrets.data["homepage_credentials"])
-}
-
-
 resource "kubernetes_namespace" "changedetection" {
   metadata {
     name = "changedetection"
@@ -23,6 +13,45 @@ resource "kubernetes_namespace" "changedetection" {
   }
 }
 
+resource "kubernetes_manifest" "external_secret" {
+  manifest = {
+    apiVersion = "external-secrets.io/v1beta1"
+    kind       = "ExternalSecret"
+    metadata = {
+      name      = "changedetection-secrets"
+      namespace = "changedetection"
+    }
+    spec = {
+      refreshInterval = "15m"
+      secretStoreRef = {
+        name = "vault-kv"
+        kind = "ClusterSecretStore"
+      }
+      target = {
+        name = "changedetection-secrets"
+      }
+      dataFrom = [{
+        extract = {
+          key = "changedetection"
+        }
+      }]
+    }
+  }
+  depends_on = [kubernetes_namespace.changedetection]
+}
+
+data "kubernetes_secret" "eso_secrets" {
+  metadata {
+    name      = "changedetection-secrets"
+    namespace = kubernetes_namespace.changedetection.metadata[0].name
+  }
+  depends_on = [kubernetes_manifest.external_secret]
+}
+
+locals {
+  homepage_credentials = jsondecode(data.kubernetes_secret.eso_secrets.data["homepage_credentials"])
+}
+
 module "tls_secret" {
   source          = "../../modules/kubernetes/setup_tls_secret"
   namespace       = kubernetes_namespace.changedetection.metadata[0].name