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

Partnership/partnership_manager.sh

@@ -141,7 +141,7 @@
 #   TAILSCALE_API_KEY / TAILSCALE_TAILNET
 #       Required when PARTNERSHIP_REMOVE_TAILSCALE=true
 #
-# master_host*.conf
+# host*.conf
 #
 #   HOST*_PARTNERSHIP_AUTH_WEBUIS
 #       Containers reconfigured on onboard/offboard. Format: "ContainerName|WebUIPort"
@@ -253,7 +253,7 @@ OWNER="${!OWNER_ID}"                                # hostname string
 MIRROR="${!MIRROR_ID}"
 # SSH_KEY (set by detect_hosts) is this server's own private key.
 # The remote accepts it because this server's PUBLIC key was installed there via ssh_setup.sh.
-# With sparse checkout, each server only has its own master_host{N}.conf — the other server's
+# With sparse checkout, each server only has its own host{N}.conf — the other server's
 # key path is never available here. Use SSH_KEY for all outbound SSH regardless of mode.
 MIRROR_SSH_KEY="$SSH_KEY"
 OWNER_SSH_KEY="$SSH_KEY"