Show when a watchdog cycle last completed

Without it the page renders zeros, all-clear pills and green dots when the
orchestrator has stopped entirely — its healthiest appearance describing a
machine with no watchdogs, against a header promising absence is never drawn as
an all-clear. The heartbeat already existed; overdue is measured against the
cron schedule rather than an assumed fifteen minutes.

Plugin/unraid/pages/watchdog.php

@@ -419,6 +419,27 @@ function _systemCard(node, cfg) {
       ? '<span style="color:#7a6a20;">off — CONF_SYNC_ENABLED</span>'
       : '<span style="color:#4caf50;">active</span>';
 
+  // ── Is anything still running? ──────────────────────────────────────────────
+  // Every other number on this card is only meaningful if a cycle actually happened. If the
+  // orchestrator stopped, the strike maps stop changing and the whole page renders zeros, "all
+  // clear" pills and green dots — its healthiest possible appearance, describing a machine with
+  // no watchdogs at all. This is the one reading that distinguishes quiet from absent, and the
+  // page's own contract says absence must never be drawn as an all-clear.
+  //
+  // stability_watchdog.sh writes the heartbeat last in the chain, so a fresh value means a whole
+  // cycle finished rather than one that started and died halfway. Overdue is measured against the
+  // schedule in force (cfg.cycle_min, read from the cron), not a constant: one missed cycle is
+  // worth noticing, two is worth alarming about.
+  const cycleMin = cfg.cycle_min || 15;
+  const lastCyc  = (node.states || {}).last_cycle || 0;
+  const cycAge   = lastCyc ? Math.max(0, Math.floor(Date.now() / 1000) - lastCyc) : null;
+  const cycCol   = cycAge == null            ? '#555'
+                 : cycAge > cycleMin * 60 * 3 ? '#ef5350'
+                 : cycAge > cycleMin * 60 * 2 ? '#ffb74d' : '#4caf50';
+  const cycTxt   = cycAge == null ? 'never' : _relTime(lastCyc);
+  const cycNote  = cycAge == null            ? ' — no cycle has completed'
+                 : cycAge > cycleMin * 60 * 2 ? ' — overdue, expected every ' + cycleMin + 'm' : '';
+
   const apiOnly   = sys.api_only === true;
   const daemonDot = sys.daemon_ok === null ? '#555' : sys.daemon_ok ? '#4caf50' : '#ef5350';
   const daemonTxt = sys.daemon_ok === null ? '—' : sys.daemon_ok ? 'daemon ok' : 'daemon err';
@@ -439,6 +460,8 @@ function _systemCard(node, cfg) {
             >${apiOnly ? 'API ONLY' : _levelLabel(level)}</span>
     </div>
     <div class="vv-wd-sec">System</div>
+    ${!apiOnly ? _row('Last cycle', `<span style="color:${cycCol}">${vvEscHtml(cycTxt)}</span>`
+                                  + `<span style="color:#3a3a3a;font-size:10px;">${vvEscHtml(cycNote)}</span>`) : ''}
     ${_row('RAM free', `<span style="color:${memCol}">${_fmtBytes(sys.mem_avail)}</span> / ${_fmtBytes(sys.mem_total)}`)}
     ${_bar(usedPct, memCol)}
     <div style="display:flex;justify-content:space-between;margin-top:1px;font-size:10px;color:#333">