Fix dead/incorrect vars and consolidate duplicated logic into common.sh

Codebase-wide audit pass: fixed real bugs (SSH hangs missing BatchMode,
local-outside-function no-ops, variable name collisions, a truncated
ratio calc, wrong state-dir path, DARK vs NO_INTERNET drift, and more),
then pulled logic that was duplicated across multiple scripts — arr
cleanup safety gates, docker restart ordering, container maintenance
stop/restart, watchdog state-file helpers, partnership role resolution,
cert expiry checks, remote node discovery, and TMDB discovery scoring —
into common.sh so each now has a single implementation.

Monitors/smart_health.sh

@@ -156,11 +156,7 @@ if [[ "$SHOW_STATUS" == true ]]; then
     for drive in /dev/sd? /dev/nvme?; do
         [[ ! -e "$drive" ]] && continue
         drive_name=$(basename "$drive")
-        ignored=false
-        for ignore in "${SMART_IGNORE_DRIVES[@]}"; do
-            [[ "$drive_name" == "$ignore" ]] && ignored=true && break
-        done
-        if [[ "$ignored" == true ]]; then
+        if is_in_list "$drive_name" "${SMART_IGNORE_DRIVES[@]}"; then
             echo "  $ICON_WARN $drive — ignored"
         else
             echo "  $ICON_SMART $drive — would check"
@@ -201,18 +197,7 @@ get_drive_temp() {
     echo "${temp:-}"
 }
 
-# Detect if a drive is SSD/NVMe (rotational=0)
-is_ssd() {
-    local drive="$1"
-    local dev_name
-    dev_name=$(basename "$drive" | sed 's/nvme[0-9]/nvme0/')
-    local rotational="/sys/block/$(basename "$drive")/queue/rotational"
-    [[ -f "$rotational" ]] && [[ "$(cat "$rotational" 2>/dev/null)" == "0" ]] && return 0
-    # NVMe is always SSD
-    [[ "$drive" == *nvme* ]] && return 0
-    return 1
-}
-
+# is_ssd() — provided by common.sh
 # ==============================================================================================
 # ━━━ SMART Health Check ━━━
 # ==============================================================================================
@@ -232,12 +217,7 @@ for drive in /dev/sd? /dev/nvme?; do
     drive_name=$(basename "$drive")
 
     # Check ignore list
-    ignored=false
-    for ignore in "${SMART_IGNORE_DRIVES[@]}"; do
-        [[ "$drive_name" == "$ignore" ]] && ignored=true && break
-    done
-
-    if [[ "$ignored" == true ]]; then
+    if is_in_list "$drive_name" "${SMART_IGNORE_DRIVES[@]}"; then
         log "$drive_name — ignored (SMART_IGNORE_DRIVES)"
         DRIVES_SKIP+=("$drive_name")
         continue