fix widespread naming errors across all docs — array_started, fallback, FALLBACK_

array_start.sh → array_started.sh (bulk rename — actual file has always been
array_started.sh; docs consistently used the wrong name across 9 files)

failover.sh → fallback.sh (bulk rename — script is Fallback/fallback.sh;
docs used the old name throughout)

FAILOVER_HOST2_RUNS_FOR_HOST1_TIER1 → FALLBACK_HOST2_COVERS_HOST1_TIER1
(README.md — wrong variable name, actual vars use FALLBACK_ prefix and
COVERS_ not RUNS_FOR_)

docker_watchdog.sh attribution: "started by array_started.sh" → "called every
minute by watchdog_orchestrator.sh" (docker_watchdog is not in ARRAY_START_SCRIPTS)

server_reboot.sh shutdown sequence: step 7 "rc.docker stop" → calls
array_stopping.sh (user_scripts, fallback, rsync, mover, docker_container_stop)

Rsync manual ARRAY_START_SCRIPTS list: removed stability_watchdog and
docker_watchdog (now in watchdog_orchestrator); failover → fallback

unRAID_Essentials/README-Unraid_Essentials.md

@@ -91,7 +91,7 @@ Graceful operations     mover_stop.sh            — clean mover stop
 
 ```
 Orchestrators/
-  array_start.sh ─────────────────────────► inotify_tuning.sh       (first in sequence)
+  array_started.sh ─────────────────────────► inotify_tuning.sh       (first in sequence)
                  ─────────────────────────► docker_syslog_filter.sh  (second)
                  ─────────────────────────► php_fpm_max_children.sh
   weekly_maintenance.sh ──────────────────► clear_logs.sh