Switch to ephemeral_disk, no host_volume required

sticky+migrate keeps data across restarts and job updates.
DATA_DIR points to NOMAD_ALLOC_DIR/data.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

citti.nomad

@@ -35,10 +35,10 @@ job "citti" {
       unlimited      = false
     }
 
-    volume "citti-data" {
-      type      = "host"
-      source    = "citti-data"
-      read_only = false
+    ephemeral_disk {
+      size    = 500
+      sticky  = true
+      migrate = true
     }
 
     service {
@@ -73,12 +73,6 @@ job "citti" {
     task "web" {
       driver = "docker"
 
-      volume_mount {
-        volume      = "citti-data"
-        destination = "/app/instance"
-        read_only   = false
-      }
-
       config {
         image      = "registry.i80.dk/gitea/citti:latest"
         ports      = ["http"]
@@ -93,7 +87,7 @@ job "citti" {
       }
 
       env {
-        DATA_DIR = "/app/instance"
+        DATA_DIR = "${NOMAD_ALLOC_DIR}/data"
         PORT     = "${NOMAD_PORT_http}"
         HOST     = "0.0.0.0"
       }