[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/coturn/module/main.tf

@@ -0,0 +1,194 @@
+variable "tls_secret_name" {}
+variable "tier" { type = string }
+variable "turn_secret" { type = string }
+variable "public_ip" { type = string }
+
+locals {
+  turn_realm = "viktorbarzin.me"
+  turn_port  = 3478
+  # Small relay range — 100 ports is plenty for a home lab (~50 concurrent streams)
+  min_port = 49152
+  max_port = 49252
+}
+
+resource "kubernetes_namespace" "coturn" {
+  metadata {
+    name = "coturn"
+    labels = {
+      tier = var.tier
+    }
+  }
+}
+
+module "tls_secret" {
+  source          = "../../../modules/kubernetes/setup_tls_secret"
+  namespace       = kubernetes_namespace.coturn.metadata[0].name
+  tls_secret_name = var.tls_secret_name
+}
+
+resource "kubernetes_config_map" "coturn_config" {
+  metadata {
+    name      = "coturn-config"
+    namespace = kubernetes_namespace.coturn.metadata[0].name
+  }
+
+  data = {
+    "turnserver.conf" = <<-EOF
+      # TURN server configuration
+      listening-port=${local.turn_port}
+      fingerprint
+      lt-cred-mech
+      use-auth-secret
+      static-auth-secret=${var.turn_secret}
+      realm=${local.turn_realm}
+      server-name=turn.${local.turn_realm}
+
+      # Network — use 0.0.0.0, coturn auto-detects pod IP
+      listening-ip=0.0.0.0
+      external-ip=${var.public_ip}
+
+      # Media relay port range (narrow — 100 ports)
+      min-port=${local.min_port}
+      max-port=${local.max_port}
+
+      # Logging
+      verbose
+      no-stdout-log
+      syslog
+
+      # Security
+      no-multicast-peers
+      no-cli
+      no-tlsv1
+      no-tlsv1_1
+
+      # Performance
+      total-quota=100
+      stale-nonce=600
+      max-bps=0
+    EOF
+  }
+}
+
+resource "kubernetes_deployment" "coturn" {
+  metadata {
+    name      = "coturn"
+    namespace = kubernetes_namespace.coturn.metadata[0].name
+    labels = {
+      app  = "coturn"
+      tier = var.tier
+    }
+  }
+
+  spec {
+    replicas = 1
+    strategy {
+      type = "RollingUpdate"
+      rolling_update {
+        max_unavailable = 0
+        max_surge       = 1
+      }
+    }
+    selector {
+      match_labels = {
+        app = "coturn"
+      }
+    }
+
+    template {
+      metadata {
+        labels = {
+          app = "coturn"
+        }
+      }
+
+      spec {
+        container {
+          name  = "coturn"
+          image = "coturn/coturn:latest"
+          args  = ["-c", "/etc/turnserver/turnserver.conf"]
+
+          # STUN/TURN signaling port
+          port {
+            name           = "turn-udp"
+            container_port = local.turn_port
+            protocol       = "UDP"
+          }
+          port {
+            name           = "turn-tcp"
+            container_port = local.turn_port
+            protocol       = "TCP"
+          }
+
+          volume_mount {
+            name       = "config"
+            mount_path = "/etc/turnserver"
+            read_only  = true
+          }
+
+          resources {
+            requests = {
+              cpu    = "100m"
+              memory = "128Mi"
+            }
+            limits = {
+              cpu    = "1"
+              memory = "512Mi"
+            }
+          }
+        }
+
+        volume {
+          name = "config"
+          config_map {
+            name = kubernetes_config_map.coturn_config.metadata[0].name
+          }
+        }
+      }
+    }
+  }
+}
+
+# LoadBalancer service with MetalLB — exposes STUN/TURN signaling + relay ports
+resource "kubernetes_service" "coturn" {
+  metadata {
+    name      = "coturn"
+    namespace = kubernetes_namespace.coturn.metadata[0].name
+    annotations = {
+      "metallb.universe.tf/loadBalancerIPs" = "10.0.20.200"
+      "metallb.universe.tf/allow-shared-ip" = "shared"
+    }
+  }
+
+  spec {
+    type = "LoadBalancer"
+    selector = {
+      app = "coturn"
+    }
+
+    # STUN/TURN signaling
+    port {
+      name        = "turn-udp"
+      port        = local.turn_port
+      target_port = local.turn_port
+      protocol    = "UDP"
+    }
+    port {
+      name        = "turn-tcp"
+      port        = local.turn_port
+      target_port = local.turn_port
+      protocol    = "TCP"
+    }
+
+    # Relay port range (49152-49252)
+    dynamic "port" {
+      for_each = range(local.min_port, local.max_port + 1)
+      content {
+        name        = "relay-${port.value}"
+        port        = port.value
+        target_port = port.value
+        protocol    = "UDP"
+      }
+    }
+  }
+}