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.

Transcodes/transcode_cleanup.sh

@@ -240,15 +240,7 @@ cleanup_location() {
 
     # Format bytes freed
     local freed_human
-    if (( bytes_freed > 1073741824 )); then
-        freed_human=$(awk "BEGIN {printf \"%.1fGB\", $bytes_freed / 1073741824}")
-    elif (( bytes_freed > 1048576 )); then
-        freed_human=$(awk "BEGIN {printf \"%.1fMB\", $bytes_freed / 1048576}")
-    elif (( bytes_freed > 0 )); then
-        freed_human="${bytes_freed}B"
-    else
-        freed_human="0B"
-    fi
+    freed_human=$(format_bytes "$bytes_freed")
 
     log "$label — removed $files_removed ($freed_human) | active(fresh): $files_too_young | streaming(lsof): $files_streaming | protected(old+open): $files_active | skipped: $files_skipped | failed: $files_failed"
 
@@ -299,7 +291,7 @@ fi
 # Post-cleanup — check if ramdisk recovered enough to flip symlink back to ramdisk
 if [[ "$DRY_RUN" == false ]] && mountpoint -q "$RAMDISK_PATH" 2>/dev/null; then
     RAMDISK_USED_KB=$(df "$RAMDISK_PATH" --output=used 2>/dev/null | tail -1 | tr -d ' ')
-    RAMDISK_USED_GB=$(awk "BEGIN {printf \"%.2f\", ${RAMDISK_USED_KB:-0} / 1048576}")
+    RAMDISK_USED_GB=$(kb_to_gb "$RAMDISK_USED_KB")
     LOW_RECOVERED=$(awk "BEGIN {print ($RAMDISK_USED_GB < $RAMDISK_LOW_GB) ? 1 : 0}")
     CURRENT_TARGET=$(grep "^current_target=" "$STATE_FILE" 2>/dev/null | cut -d= -f2)