unRAID_Essentials echo/log audit pass + exit traps

Exit traps: resource_watchdog registers/clears trap for stopped containers;
server_reboot registers trap to restart Docker service on abort; system_watchdog
records containers before bulk stop and registers trap to restart if reboot aborts.

echo/log audit: status conclusions, nothing-to-do, and clean-cycle confirmations
→ echo across clear_logs, docker_syslog_filter, mover_stop, php_fpm_max_children,
rsync_stop, user_scripts_stop. resource_watchdog: disabled flag, restore-level
messages, pressure status → echo. system_watchdog: clean-cycle summary → echo.
Manual-Unraid_Essentials.md: added Output Tiers section.

unRAID_Essentials/Manual-Unraid_Essentials.md

@@ -25,6 +25,22 @@ adding or reordering scripts at array start.
 
 ---
 
+## Output Tiers
+
+All scripts use a two-tier output model: `echo` lines are always visible; `log`
+lines only appear when `--log` is passed.
+
+**Daemon scripts** (`system_watchdog.sh`, `resource_watchdog.sh`, `webgui_restart.sh`):
+run on every cycle. Without `--log`, only state transitions, warnings, errors, and
+the clean-cycle conclusion line are visible. Per-check detail suppressed.
+
+**One-shot scripts** (`clear_logs.sh`, `docker_syslog_filter.sh`, `inotify_tuning.sh`,
+`mover_stop.sh`, `php_fpm_max_children.sh`, `rsync_stop.sh`, `server_reboot.sh`,
+`user_scripts_stop.sh`): without `--log`, section headers, per-step results, and the
+final summary are visible. Per-item detail suppressed.
+
+---
+
 ## ARRAY_START_SCRIPTS Order
 
 > **The order of scripts in ARRAY_START_SCRIPTS matters for three of these