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.

System_Essentials/conf_cache_save.sh

@@ -47,7 +47,7 @@ parse_args "$@"
 detect_hosts
 require_partnership
 
-RAM_CACHE="/tmp/.cache/vv/d"
+RAM_CACHE="$CONF_RAM_CACHE_DIR"
 SAVE_DIR="$PERSISTENT_CONF_CACHE"
 
 [[ "$DRY_RUN" == true ]] && warn "DRY RUN — no files will be written"
@@ -61,7 +61,7 @@ saved=0
 for conf in "$RAM_CACHE"/host*.conf; do
     [[ -f "$conf" ]] || continue
     base="$(basename "$conf")"
-    [[ "${base,,}" == "${MY_ID,,}.conf" ]] && continue
+    is_own_conf_file "$base" && continue
 
     if [[ "$DRY_RUN" == true ]]; then
         warn "DRY RUN — would save $base → $SAVE_DIR/"