feat: organize Grafana dashboards into folders

Enable sidecar folderAnnotation + foldersFromFilesStructure to group
26 dashboards into 5 managed folders:

- Cluster (6): k8s health, API server, nodes, pods, kube-state-metrics
- Networking (6): CoreDNS, Technitium, Headscale, ingress, network traffic
- Hardware (5): node-exporter, proxmox, iDRAC, UPS, NVIDIA GPU
- Operations (4): backup health, registry, audit logs, Loki
- Applications (2): realestate-crawler, qBittorrent

Dashboard-to-folder mapping defined in grafana.tf locals block.
External stacks (headscale, technitium) annotated individually.

stacks/headscale/modules/headscale/main.tf

@@ -433,6 +433,9 @@ resource "kubernetes_config_map" "grafana_headscale_dashboard" {
     labels = {
       grafana_dashboard = "1"
     }
+    annotations = {
+      grafana_folder = "Networking"
+    }
   }
   data = {
     "headscale.json" = file("${path.module}/dashboards/headscale.json")

stacks/monitoring/modules/monitoring/grafana.tf

@@ -102,6 +102,41 @@ resource "kubernetes_manifest" "grafana_db_creds" {
   }
 }
 
+locals {
+  # Dashboard folder assignments
+  dashboard_folders = {
+    # Cluster & Kubernetes
+    "api_server.json"            = "Cluster"
+    "cluster_health.json"        = "Cluster"
+    "nodes.json"                 = "Cluster"
+    "pods.json"                  = "Cluster"
+    "kube-state-metrics.json"    = "Cluster"
+    # Networking & DNS
+    "caretta-dashboard.json"     = "Networking"
+    "core_dns.json"              = "Networking"
+    "technitium-dns.json"        = "Networking"
+    "nginx_ingress.json"         = "Networking"
+    "network_traffic.json"       = "Networking"
+
+    # Hardware & Host
+    "node_exporter_full.json"    = "Hardware"
+    "proxmox_node_exporter.json" = "Hardware"
+    "idrac.json"                 = "Hardware"
+    "ups.json"                   = "Hardware"
+    "nvidia.json"                = "Hardware"
+
+    # Operations
+    "backup_health.json"         = "Operations"
+    "registry.json"              = "Operations"
+    "loki.json"                  = "Operations"
+    "k8s-audit.json"             = "Operations"
+
+    # Applications
+    "qbittorrent.json"           = "Applications"
+    "realestate-crawler.json"    = "Applications"
+  }
+}
+
 resource "kubernetes_config_map" "grafana_dashboards" {
   for_each = fileset("${path.module}/dashboards", "*.json")
 
@@ -111,6 +146,9 @@ resource "kubernetes_config_map" "grafana_dashboards" {
     labels = {
       grafana_dashboard = "1"
     }
+    annotations = {
+      grafana_folder = lookup(local.dashboard_folders, each.value, "General")
+    }
   }
   data = {
     (each.value) = file("${path.module}/dashboards/${each.value}")

stacks/monitoring/modules/monitoring/grafana_chart_values.yaml

@@ -53,6 +53,9 @@ sidecar:
   dashboards:
     enabled: true
     label: "grafana_dashboard"
+    folderAnnotation: "grafana_folder"
+    provider:
+      foldersFromFilesStructure: true
 dashboardProviders:
   dashboardproviders.yaml:
     apiVersion: 1

stacks/technitium/modules/technitium/main.tf

@@ -352,6 +352,9 @@ resource "kubernetes_config_map" "grafana_technitium_dashboard" {
     labels = {
       grafana_dashboard = "1"
     }
+    annotations = {
+      grafana_folder = "Networking"
+    }
   }
   data = {
     "technitium-dns.json" = file("${path.module}/dashboards/technitium-dns.json")