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.

Docker_Essentials/docker_container_stop.sh

@@ -186,9 +186,7 @@ FAILED=()
 
 for container in "${RUNNING[@]}"; do
     [[ -z "$container" ]] && continue
-    local c_start
     c_start=$(date +%s)
-    local c_image
     c_image=$(docker inspect --format '{{.Config.Image}}' "$container" 2>/dev/null || echo "unknown")
     log "━━━ $ICON_CONTAINERS $container ($c_image) ━━━"