feat: right-size VM 115 config and add --hosts flag to audit script

Reduce VM 115 (docker-sba) from 16 vCPUs (2×8) to 8 vCPUs (1×8) to
match actual workload (0.06 load/core). Add --hosts flag to
homelab-audit.sh for targeted post-change audits.

Closes #18

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

monitoring/scripts/homelab-audit.sh

@@ -44,7 +44,7 @@ while [[ $# -gt 0 ]]; do
       ;;
     --hosts)
       if [[ $# -lt 2 ]]; then
-        echo "Error: --hosts requires an argument" >&2
+        echo "Error: --hosts requires an argument (label:ip,label:ip,...)" >&2
         exit 1
       fi
       HOSTS_FILTER="$2"
@@ -492,20 +492,24 @@ main() {
 
   if [[ -n "$HOSTS_FILTER" ]]; then
     # --hosts mode: audit specified hosts directly, skip Proxmox inventory
+    # Accepts comma-separated entries; each entry may be plain hostname or label:ip
     local check_proxmox=0
     IFS=',' read -ra filter_hosts <<<"$HOSTS_FILTER"
-    for host in "${filter_hosts[@]}"; do
-      [[ "$host" == "proxmox" ]] && check_proxmox=1
+    for entry in "${filter_hosts[@]}"; do
+      local label="${entry%%:*}"
+      [[ "$label" == "proxmox" ]] && check_proxmox=1
     done
     if ((check_proxmox)); then
       echo "  Checking Proxmox backup recency..."
       check_backup_recency
     fi
-    for host in "${filter_hosts[@]}"; do
-      echo "  Auditing $host..."
-      parse_and_report "$host" "$host"
-      check_cert_expiry "$host" "$host"
-      AUDITED_HOSTS+=("$host")
+    for entry in "${filter_hosts[@]}"; do
+      local label="${entry%%:*}"
+      local addr="${entry#*:}"
+      echo "  Auditing $label ($addr)..."
+      parse_and_report "$label" "$addr"
+      check_cert_expiry "$label" "$addr"
+      AUDITED_HOSTS+=("$label")
       ((host_count++)) || true
     done
   else