[ci skip] Move Terraform modules into stack directories

Move all 88 service modules (66 individual + 22 platform) from
modules/kubernetes/<service>/ into their corresponding stack directories:

- Service stacks: stacks/<service>/module/
- Platform stack: stacks/platform/modules/<service>/

This collocates module source code with its Terragrunt definition.
Only shared utility modules remain in modules/kubernetes/:
ingress_factory, setup_tls_secret, dockerhub_secret, oauth-proxy.

All cross-references to shared modules updated to use correct
relative paths. Verified with terragrunt run --all -- plan:
0 adds, 0 destroys across all 68 stacks.

stacks/servarr/module/main.tf

@@ -0,0 +1,68 @@
+variable "tls_secret_name" {}
+variable "tier" { type = string }
+variable "aiostreams_database_connection_string" { type = string }
+
+resource "kubernetes_namespace" "servarr" {
+  metadata {
+    name = "servarr"
+    labels = {
+      tier = var.tier
+    }
+  }
+}
+
+module "tls_secret" {
+  source          = "../../../modules/kubernetes/setup_tls_secret"
+  namespace       = kubernetes_namespace.servarr.metadata[0].name
+  tls_secret_name = var.tls_secret_name
+}
+
+
+# module "readarr" {
+#   source          = "./readarr"
+#   tls_secret_name = var.tls_secret_name
+#   tier = var.tier
+# }
+
+module "prowlarr" {
+  source          = "./prowlarr"
+  tls_secret_name = var.tls_secret_name
+  tier            = var.tier
+}
+
+module "qbittorrent" {
+  source          = "./qbittorrent"
+  tls_secret_name = var.tls_secret_name
+  tier            = var.tier
+}
+
+module "flaresolverr" {
+  source          = "./flaresolverr"
+  tls_secret_name = var.tls_secret_name
+  tier            = var.tier
+}
+
+# module "lidarr" {
+#   source          = "./lidarr"
+#   tls_secret_name = var.tls_secret_name
+# tier            = var.tier
+# }
+
+# module "soulseek" {
+#   source          = "./soulseek"
+#   tls_secret_name = var.tls_secret_name
+# tier            = var.tier
+# }
+
+module "listenarr" {
+  source          = "./listenarr"
+  tls_secret_name = var.tls_secret_name
+  tier            = var.tier
+}
+
+module "aiostreams" {
+  source                                = "./aiostreams"
+  tls_secret_name                       = var.tls_secret_name
+  aiostreams_database_connection_string = var.aiostreams_database_connection_string
+  tier                                  = var.tier
+}