Make all arr library-list fetches cache-first with live fallback

Every script that fetches the full Lidarr/Sonarr/Radarr tracked-library
list now goes through arr_get_tracked_data() instead of hitting the API
directly -- cache-first when fresh, live fetch as fallback when stale,
waits out an active rescan before either. Per-item file data (trackFile/
episodefile/moviefile) stays live-only everywhere, since that's the
actual disk-truth these scripts' decisions depend on and was never part
of what's cached.

Also adds arr_cache_prefill.sh to CRITICAL_MAINTENANCE_SCRIPTS (30min
tier) with a short 1min wait ceiling, so the cache stays consistently
fresh instead of only refreshing whenever some other script happens to
write through. A full cache refresh for all three arrs measured at ~12s
total live -- nothing like the multi-hour cost of an actual rescan.

Arrs_Stack/sonarr_tvdb_removed.sh

@@ -152,8 +152,10 @@ if ! curl -sf --connect-timeout 5 --max-time 10 \
     exit 1
 fi
 
-SERIES=$(curl -sf --connect-timeout 5 --max-time 30 \
-    "$SONARR_URL/api/v3/series?apikey=$SONARR_API_KEY" 2>/dev/null)
+# Cache-first — arr_get_tracked_data() serves the shared cache when it's fresh (kept current
+# every 30min by arr_cache_prefill.sh in CRITICAL_MAINTENANCE_SCRIPTS), falls back to a live
+# fetch when it's stale, and waits out an active rescan before either.
+SERIES=$(arr_get_tracked_data "sonarr" "$SONARR_URL" "$SONARR_API_KEY" "v3")
 
 if [[ -z "$SERIES" || "$SERIES" == "null" ]]; then
     error "Sonarr series API returned empty"