Structural reorganization: watchdog taxonomy + server_reboot integration

Watchdog renames and moves:
  system_watchdog.sh → stability_watchdog.sh (last line of defense — reboots)
  storage_watchdog.sh → Watchdogs/System/storage_watchdog.sh
  webgui_restart.sh → Watchdogs/System/webgui_watchdog.sh (renamed to match folder convention)

New thin orchestrator:
  Watchdogs/system_watchdog.sh — runs SYSTEM_WATCHDOG_SCRIPTS from master.conf
  Sits between docker_watchdog and stability_watchdog in the orchestrator tier chain
  System/ subfolder is the growth seam for future system component watchdogs

master.conf:
  WATCHDOG_ORCHESTRATOR_SCRIPTS updated — storage removed, system_watchdog added as tier
  SYSTEM_WATCHDOG_SCRIPTS array added — storage + webgui

server_reboot.sh:
  Calls array_stopping.sh before VM shutdown for guaranteed safe array stop
  Removed raw rc.docker stop and exit trap — orchestrator owns container shutdown

Watchdogs/Manual-Watchdogs.md

@@ -637,5 +637,5 @@ grep "system_watchdog" /var/log/syslog | tail -20
 Orchestrators/watchdog_orchestrator.sh --status
 
 # Run the slow watchdog directly with --log to see where it's hanging:
-Watchdogs/system_watchdog.sh --log --dry-run
+Watchdogs/stability_watchdog.sh --log --dry-run
 ```