[ci skip] Implement multi-user Kubernetes access with OIDC

- Add RBAC module (modules/kubernetes/rbac/) with admin, power-user,
  and namespace-owner roles, API server OIDC flags, and audit logging
- Add self-service portal (modules/kubernetes/k8s-portal/) SvelteKit app
  with kubeconfig download and setup instructions
- Configure Alloy to collect audit logs from kube-apiserver
- Add Grafana dashboard for Kubernetes audit log visualization
- Configure Authentik OIDC provider with groups scope mapping
- Wire up k8s_users and ssh_private_key variables through module chain

modules/kubernetes/k8s-portal/main.tf

@@ -0,0 +1,105 @@
+variable "tls_secret_name" {}
+variable "tier" { type = string }
+
+resource "kubernetes_namespace" "k8s_portal" {
+  metadata {
+    name = "k8s-portal"
+    labels = {
+      tier = var.tier
+    }
+  }
+}
+
+module "tls_secret" {
+  source          = "../setup_tls_secret"
+  namespace       = kubernetes_namespace.k8s_portal.metadata[0].name
+  tls_secret_name = var.tls_secret_name
+}
+
+resource "kubernetes_config_map" "k8s_portal_config" {
+  metadata {
+    name      = "k8s-portal-config"
+    namespace = kubernetes_namespace.k8s_portal.metadata[0].name
+  }
+
+  data = {
+    # CA cert extracted from kubeconfig — will be populated with cluster CA cert
+    "ca.crt" = ""
+  }
+}
+
+resource "kubernetes_deployment" "k8s_portal" {
+  metadata {
+    name      = "k8s-portal"
+    namespace = kubernetes_namespace.k8s_portal.metadata[0].name
+    labels = {
+      app  = "k8s-portal"
+      tier = var.tier
+    }
+  }
+
+  spec {
+    replicas = 1
+    selector {
+      match_labels = {
+        app = "k8s-portal"
+      }
+    }
+
+    template {
+      metadata {
+        labels = {
+          app = "k8s-portal"
+        }
+      }
+
+      spec {
+        container {
+          name  = "portal"
+          image = "viktorbarzin/k8s-portal:latest"
+          port {
+            container_port = 3000
+          }
+
+          volume_mount {
+            name       = "config"
+            mount_path = "/config"
+            read_only  = true
+          }
+        }
+
+        volume {
+          name = "config"
+          config_map {
+            name = kubernetes_config_map.k8s_portal_config.metadata[0].name
+          }
+        }
+      }
+    }
+  }
+}
+
+resource "kubernetes_service" "k8s_portal" {
+  metadata {
+    name      = "k8s-portal"
+    namespace = kubernetes_namespace.k8s_portal.metadata[0].name
+  }
+
+  spec {
+    selector = {
+      app = "k8s-portal"
+    }
+    port {
+      port        = 80
+      target_port = 3000
+    }
+  }
+}
+
+module "ingress" {
+  source          = "../ingress_factory"
+  namespace       = kubernetes_namespace.k8s_portal.metadata[0].name
+  name            = "k8s-portal"
+  tls_secret_name = var.tls_secret_name
+  protected       = true # Require Authentik login
+}