Watchdogs/ folder + host conf rename

Move all watchdog scripts to a dedicated Watchdogs/ folder:
  Docker_Essentials/docker_watchdog.sh   → Watchdogs/
  unRAID_Essentials/system_watchdog.sh   → Watchdogs/
  unRAID_Essentials/resource_watchdog.sh → Watchdogs/
  Orchestrators/watchdog_orchestrator.sh → Watchdogs/
  Tools/watchdog_skip_list_manager.sh    → Watchdogs/

Rename host config files:
  master_host1.conf → host1.conf
  master_host2.conf → host2.conf

Update all references across the ecosystem:
  master.conf: WATCHDOG_ORCHESTRATOR_SCRIPTS paths → Watchdogs/
  load_config.sh: host*.conf glob + all comments
  git_pull_execute.sh: sparse checkout glob + all comments
  Partnership/ssh_setup.sh: HOST_CONF path construction
  user_script_plug-in.sh: all script paths + per-host conf path
  common.sh, README.md, README-User_Script_Plug-in.md: comment refs
  All Partnership, Fallback, Monitors, Transcodes, Tools scripts: comment refs

Docker_Essentials/docker_update.sh

@@ -95,7 +95,7 @@
 #       Container names for emby and critical-data profiles — excluded from
 #       remainder mode (already updated by the weekly sync window)
 #
-# master_host*.conf
+# host*.conf
 #
 #   HOST*_DAILY_RESTART_CONTAINERS
 #       Containers updated in normal mode. Aliased by detect_hosts() →
@@ -205,7 +205,7 @@ else
 
     if [[ ${#DAILY_RESTART_CONTAINERS[@]} -eq 0 ]]; then
         warn "DAILY_RESTART_CONTAINERS is empty for $MY_ID — nothing to update"
-        warn "Check HOST${MY_ID#HOST}_DAILY_RESTART_CONTAINERS in master_host*.conf"
+        warn "Check HOST${MY_ID#HOST}_DAILY_RESTART_CONTAINERS in host*.conf"
         exit 0
     fi