Add server hardware/network detail view with Proxmox sync and agent reporting

Servers & Tasks only tracked scheduled tasks — there was no overview of
the servers themselves and no way to see CPU/RAM/disk/IP info. Add a
clickable server overview (visible to every role, not just admins) that
opens a per-server detail page.

- servers table gains an agent-reported hardware/network snapshot
  (IPs, CPU model/cores/load, memory, disks) and an optional link to a
  Proxmox VM/LXC (integration + node + guest type + vmid).
- Proxmox adapter gains getGuestDetail(): live cores/memory/disk from
  /config, live cpu/mem/uptime from /status/current, and IPs (LXC net
  config directly, QEMU via a best-effort guest-agent call that degrades
  gracefully when the agent isn't installed).
- New GET /api/servers/:id/detail combines whichever hardware source
  applies (live Proxmox vs. last agent report) with a DNS reverse-lookup
  against the DNS module's own record cache, so matching hostnames show
  up next to each IP. New PATCH /api/servers/:id manages the Proxmox
  link.
- agent/linux/report-tasks.sh now also collects and reports IPs,
  CPU/memory/disk info on every check-in (load-average-based CPU number,
  not instantaneous, to keep the agent a cheap oneshot).
- Extracted the per-server task table into a shared ServerTaskTable
  component so the all-servers view and the new detail page render
  tasks identically.

Verified server-side end-to-end against the real dev server (agent
report -> detail endpoint -> DNS match) and the Proxmox adapter against
a mock HTTPS server covering LXC/QEMU config parsing and the
guest-agent-unavailable fallback.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

agent/linux/report-tasks.sh

@@ -173,16 +173,67 @@ collect_systemd_timers() {
   done < <(jq -c '.[]' <<<"$timers_json")
 }
 
+collect_system_info() {
+  local ip_json="[]"
+  if command -v ip >/dev/null 2>&1; then
+    ip_json=$(ip -4 -o addr show scope global 2>/dev/null \
+      | awk '{print $4}' | cut -d/ -f1 \
+      | jq -R -s -c 'split("\n") | map(select(length > 0))')
+  fi
+
+  local cpu_model="" cpu_cores=0 cpu_load_percent="null"
+  cpu_model=$(grep -m1 "model name" /proc/cpuinfo 2>/dev/null | cut -d: -f2- | sed 's/^ *//')
+  cpu_cores=$(nproc 2>/dev/null || echo 0)
+  if [[ -r /proc/loadavg && "$cpu_cores" -gt 0 ]]; then
+    local load1
+    load1=$(awk '{print $1}' /proc/loadavg)
+    cpu_load_percent=$(awk -v l="$load1" -v c="$cpu_cores" 'BEGIN { printf "%.1f", (l/c)*100 }')
+  fi
+
+  local mem_total=0 mem_used=0
+  if command -v free >/dev/null 2>&1; then
+    read -r mem_total mem_used < <(free -b | awk '/^Mem:/ {print $2, $3}')
+  fi
+
+  local disks_json="[]"
+  if command -v df >/dev/null 2>&1; then
+    disks_json=$(df -B1 --output=target,size,used -x tmpfs -x devtmpfs -x squashfs -x overlay 2>/dev/null \
+      | tail -n +2 \
+      | awk '{print $1"\t"$2"\t"$3}' \
+      | jq -R -s -c '
+          split("\n") | map(select(length > 0) | split("\t")) |
+          map({mount: .[0], size_bytes: (.[1]|tonumber), used_bytes: (.[2]|tonumber)})
+        ')
+  fi
+
+  SYSTEM_JSON=$(jq -n \
+    --argjson ip_addresses "$ip_json" \
+    --arg cpu_model "$cpu_model" \
+    --argjson cpu_cores "${cpu_cores:-0}" \
+    --argjson cpu_load_percent "$cpu_load_percent" \
+    --argjson mem_total_bytes "${mem_total:-0}" \
+    --argjson mem_used_bytes "${mem_used:-0}" \
+    --argjson disks "$disks_json" \
+    '{
+      ip_addresses: $ip_addresses,
+      cpu: { model: $cpu_model, cores: $cpu_cores, load_percent: $cpu_load_percent },
+      memory: { total_bytes: $mem_total_bytes, used_bytes: $mem_used_bytes },
+      disks: $disks
+    }')
+}
+
 collect_cron
 collect_systemd_timers
+collect_system_info
 
 HOSTNAME_VALUE=$(hostname -f 2>/dev/null || hostname)
 PAYLOAD=$(jq -n \
   --arg hostname "$HOSTNAME_VALUE" \
   --arg os_type "linux" \
   --arg reported_at "$(date -u +"%Y-%m-%dT%H:%M:%SZ")" \
+  --argjson system "$SYSTEM_JSON" \
   --argjson tasks "$TASKS_JSON" \
-  '{hostname: $hostname, os_type: $os_type, reported_at: $reported_at, tasks: $tasks}')
+  '{hostname: $hostname, os_type: $os_type, reported_at: $reported_at, system: $system, tasks: $tasks}')
 
 if [[ "$DRY_RUN" == "1" ]]; then
   echo "$PAYLOAD" | jq .