Make proxmox_storage a global setting instead of a per-job snapshot

Backup jobs stored their own proxmox_storage column, copied from
settings at creation time and never resynced. process_backup preferred
that frozen job value, so changing Settings > Proxmox storage had no
effect on existing jobs. Drop the per-job column and always use the
current global setting when starting a backup.

Also copies AGENTS.md to CLAUDE.md.

frontend/src/App.vue

@@ -28,7 +28,6 @@ type Job = {
   node: string
   enabled: number | boolean
   cron_schedule: string
-  proxmox_storage: string
   backup_mode: string
   compression: string
   retention_type: string
@@ -102,7 +101,6 @@ const editingJobId = ref<number | null>(null)
 const editJobForm = reactive({
   enabled: true,
   cron_schedule: '',
-  proxmox_storage: '',
   backup_mode: '',
   compression: '',
   retention_type: 'days',
@@ -205,7 +203,6 @@ async function createJob() {
     node: guest.node,
     enabled: newJob.enabled,
     cron_schedule: newJob.cron_schedule,
-    proxmox_storage: settings.proxmox_storage,
     backup_mode: settings.default_backup_mode,
     compression: settings.default_compression,
     retention_type: newJob.retention_type,
@@ -244,7 +241,6 @@ function beginEditJob(job: Job) {
   editingJobId.value = job.id
   editJobForm.enabled = Boolean(job.enabled)
   editJobForm.cron_schedule = job.cron_schedule
-  editJobForm.proxmox_storage = job.proxmox_storage
   editJobForm.backup_mode = job.backup_mode
   editJobForm.compression = job.compression
   editJobForm.retention_type = job.retention_type
@@ -265,7 +261,6 @@ async function saveJob(job: Job) {
       body: JSON.stringify({
         enabled: editJobForm.enabled,
         cron_schedule: editJobForm.cron_schedule,
-        proxmox_storage: editJobForm.proxmox_storage,
         backup_mode: editJobForm.backup_mode,
         compression: editJobForm.compression,
         retention_type: editJobForm.retention_type,
@@ -528,8 +523,7 @@ onUnmounted(() => {
                   <td class="space-y-1 py-2">
                     <div class="rounded border border-slate-700 bg-slate-950 px-2 py-1 text-xs text-slate-300">Editing job #{{ j.id }}</div>
                     <input v-model="editJobForm.cron_schedule" class="w-full" />
-                    <div class="grid gap-1 md:grid-cols-3">
-                      <input v-model="editJobForm.proxmox_storage" placeholder="storage" />
+                    <div class="grid gap-1 md:grid-cols-2">
                       <select v-model="editJobForm.backup_mode"><option>snapshot</option><option>suspend</option><option>stop</option></select>
                       <select v-model="editJobForm.compression"><option>zstd</option><option>gzip</option><option>lzo</option><option>none</option></select>
                     </div>
@@ -551,7 +545,7 @@ onUnmounted(() => {
                   </td>
                 </template>
                 <template v-else>
-                  <td class="py-2">{{ j.cron_schedule }}<div class="text-xs text-slate-500">job #{{ j.id }} · {{ j.proxmox_storage }} · {{ j.backup_mode }} · {{ j.compression }} · {{ j.enabled ? 'enabled' : 'disabled' }}</div></td>
+                  <td class="py-2">{{ j.cron_schedule }}<div class="text-xs text-slate-500">job #{{ j.id }} · {{ j.backup_mode }} · {{ j.compression }} · {{ j.enabled ? 'enabled' : 'disabled' }}</div></td>
                   <td class="py-2">{{ j.retention_type }} {{ j.retention_value }}</td>
                   <td class="py-2">
                     <div>{{ fmtDate(j.next_run_at) }}</div>