feat: watchdog architecture v2 — resource manager + single-pass orchestrator

Introduce a four-layer self-healing stack replacing the continuous-loop watchdogs:

- resource_manager.sh (new): single-pass pressure reduction layer; throttles
  SABnzbd/qBit at level 1, docker-pauses background containers at level 2,
  docker-stops optional containers and signals docker_watchdog to defer at
  level 3; graduated recovery with hysteresis

- watchdog_orchestrator.sh (new, Orchestrators/): runs resource_manager →
  docker_watchdog → system_watchdog in sequence; intended for per-minute cron
  via User Scripts; startup grace, acquire_lock to prevent pile-up, heartbeat

- docker_watchdog.sh: de-looped to single-pass; daemon strikes persisted to
  state file across runs; cross-script coordination reads RM_STATE_FILE instead
  of SYS_WATCHDOG_STATE_FILE

- system_watchdog.sh: de-looped to single-pass; stripped of all container
  management (shutdown_non_essential_containers removed); reboot-only last resort

- master.conf: removed system_watchdog and docker_watchdog from
  ARRAY_START_SCRIPTS; added WATCHDOG ORCHESTRATOR and RESOURCE MANAGER sections

- master_host1.conf: added RM_PAUSE_CONTAINERS and RM_STOP_CONTAINERS arrays

- common.sh: aliased RM_PAUSE_CONTAINERS and RM_STOP_CONTAINERS via detect_hosts()

- continuous_scripts_status.sh: moved to Tools/ (preserved for future use)

- sunday_morning_coffee_report.sh: watchdog section updated to use state file
  mtime checks instead of is_running; added Resource Manager subsection;
  fixed mem_shutdown grep filter pointing to wrong state file

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

common.sh

@@ -572,6 +572,8 @@ detect_hosts() {
     _alias_array "PARTNERSHIP_AUTH_WEBUIS"
     _alias_array "PARTNERSHIP_MIRROR_BACKUPS"
     _alias_array "PARTNERSHIP_OWN_CONTAINERS"
+    _alias_array "RM_PAUSE_CONTAINERS"
+    _alias_array "RM_STOP_CONTAINERS"
 
     # ── Set array aliases — associative arrays ────────────────────────────────
     # Associative arrays cannot be copied with eval — must be rebuilt key by key