watchdogs: add echo banners to network/storage/stability

All watchdog scripts now open with a consistent echo banner:
  ━━━ <icon> <Name> Watchdog — <timestamp> ━━━

Previously network and storage used a quiet log() line (no separator),
and stability_watchdog used warn() which made every run show ⚠️.

Also: network_watchdog now logs "Network healthy ✅" on clean exit,
and stability_watchdog's reboot-trigger block now says "Stability"
instead of the old "System Watchdog" label.

Watchdogs/System/network_watchdog.sh

@@ -199,7 +199,7 @@ fi
 # ==============================================================================================
 # ━━━ Check 1 — Internet Connectivity ━━━
 # ==============================================================================================
-log "Network watchdog — $MY_ID — $(date '+%H:%M:%S')"
+echo "━━━ $ICON_NET Network Watchdog — $(date '+%Y-%m-%d %H:%M:%S') ━━━"
 
 ISSUES=0
 
@@ -310,5 +310,9 @@ fi
 # ==============================================================================================
 # ━━━ Exit ━━━
 # ==============================================================================================
-[[ "$ISSUES" -gt 0 ]] && exit 1
-exit 0
+if [[ "$ISSUES" -gt 0 ]]; then
+    exit 1
+else
+    log "Network healthy ✅ ($(date '+%H:%M:%S'))"
+    exit 0
+fi