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/README-Docker_Essentials.md

@@ -275,7 +275,7 @@ Array starts
             reads system_watchdog state (RAM emergency deferral)
             │
             │  (on skip list event → operator uses)
-            └── Tools/watchdog_skip_list_manager.sh
+            └── Watchdogs/watchdog_skip_list_manager.sh
                     inspect state, clear after fixing root cause
 
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