Monitors echo/log audit pass

Status conclusions and clean-check summaries → echo: backup_verify (pre-flight
passed, all files match), bandwidth_monitor (logged transfer entry),
cert_monitor/smart_health (all healthy), system_tuning_monitor (snapshot written),
weekly_health_digest (smart no-findings exit, digest sent), zfs_memory_snapshot
(all pools ONLINE, all checks within thresholds). Manual-Monitors.md: added
Output Tiers section.

Monitors/weekly_health_digest.sh

@@ -341,7 +341,7 @@ fi
 # ── Smart profile — exit silently if nothing to report ────────────────────────────────────────
 # ==============================================================================================
 if [[ "$DIGEST_PROFILE" == "smart" && "$SHOULD_SEND" == false ]]; then
-    log "Profile: smart — no findings worth reporting — silent exit"
+    echo "Profile: smart — no findings worth reporting — silent exit"
     exit 0
 fi
 
@@ -378,5 +378,5 @@ if [[ "$DRY_RUN" == true ]]; then
     warn "DRY RUN — digest generated but not sent"
 elif [[ "$SHOULD_SEND" == true ]]; then
     notify "$NOTIFY_MSG" "Health Digest" "$NOTIFY_SEV"
-    log "Digest sent"
+    echo "Digest sent"
 fi