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_onboard.sh

@@ -45,7 +45,7 @@
 #
 # Dependency ordering in the auth stack is owner-enforced
 #   PARTNERSHIP_AUTH_STACK order matters: Mariadb and Redis must come before Authelia.
-#   The array is ordered correctly in master_host1.conf. After each Mariadb/Redis deploy,
+#   The array is ordered correctly in host1.conf. After each Mariadb/Redis deploy,
 #   the script waits for the container to be healthy before continuing. This is a remote
 #   health check — the container must be running (or report healthy) before the next
 #   dependent is deployed.
@@ -73,7 +73,7 @@
 # CONFIGURATION
 # ==============================================================================================
 #
-# master_host*.conf
+# host*.conf
 #
 #   HOST*_PARTNERSHIP_AUTH_STACK
 #       XML filenames (from this server's templates-user/) to push and deploy on the
@@ -82,7 +82,7 @@
 #
 #   HOST*_PARTNERSHIP_REPLACE_CONTAINERS
 #       Containers to stop on the mirror before deploying the auth stack.
-#       Defined in the MIRROR's own conf (master_host*.conf on HOST2) — never in HOST1's conf.
+#       Defined in the MIRROR's own conf (host*.conf on HOST2) — never in HOST1's conf.
 #       Read live from the mirror via SSH during Step 3 (sources mirror's load_config.sh at
 #       the same $SCRIPTS_ROOT path — convention: both servers use the same repo location).
 #       Leave empty on HOST2 if no conflicting containers exist (fresh mirror: nothing to stop).
@@ -171,7 +171,7 @@ OWNER="${!OWNER_ID}"
 MIRROR="${!MIRROR_ID}"
 # SSH_KEY (set by detect_hosts) is this server's own private key.
 # The remote accepts it because this server's PUBLIC key was installed there via ssh_setup.sh.
-# HOST{N}_SSH_KEY lives in master_host{N}.conf — with sparse checkout, the other server's
+# HOST{N}_SSH_KEY lives in host{N}.conf — with sparse checkout, the other server's
 # conf is never present here. Always use SSH_KEY (local private key) for outbound SSH.
 MIRROR_SSH_KEY="$SSH_KEY"
 
@@ -359,7 +359,7 @@ wait_for_container_healthy() {
 #
 # SSHes to the mirror, sources its load_config.sh at the same $SCRIPTS_ROOT path (both servers
 # use the same convention), and reads the named config array from the mirror's own conf.
-# HOST2's container list stays in HOST2's master_host2.conf — not duplicated in HOST1's conf.
+# HOST2's container list stays in HOST2's host2.conf — not duplicated in HOST1's conf.
 # Fails gracefully if scripts aren't present yet or the array is empty (nothing to stop).
 #
 # deploy_container_from_xml() already stops/removes containers with the same name as what's
@@ -547,7 +547,7 @@ if [[ "$SKIP_AUTH_STACK" == true ]]; then
     warn "Skipping (--skip-auth-stack)"
 elif [[ ${#PARTNERSHIP_AUTH_STACK[@]} -eq 0 ]]; then
     warn "PARTNERSHIP_AUTH_STACK not set in ${MY_ID} conf — skipping auth stack deploy"
-    warn "Add HOST${MY_ID: -1}_PARTNERSHIP_AUTH_STACK to master_host${MY_ID: -1}.conf"
+    warn "Add HOST${MY_ID: -1}_PARTNERSHIP_AUTH_STACK to host${MY_ID: -1}.conf"
     STEP_AUTH_OK=false
 else
     deploy_xml_stack PARTNERSHIP_AUTH_STACK