feat: Sentinel节点卡片添加HTTP链路延迟显示(横版左下角/网格右上角)

plugins/sentinel/dashboard.html

@@ -294,6 +294,7 @@
                 (sysInfo.trim() ? '<div class="node-sys">'+esc(sysInfo)+'</div>' : '')+
                 '<div class="node-url">'+esc(n.url||'')+'</div>'+
                 (n.notes ? '<div class="node-notes">📝 '+esc(n.notes)+'</div>' : '')+
+                '<div class="node-latency" style="font-size:.7rem;color:var(--text-dim);margin-top:4px">⏱ —</div>'+
               '</div>'+
               '<div class="col-right-stack">'+
                 '<div class="mtr" id="mtr-'+id+'-cpu"><div class="mtr-data"><span class="rlabel">CPU</span> <span class="rval cpu-val">0%</span></div><canvas id="'+id+'-cpu" height="60"></canvas></div>'+
@@ -311,7 +312,10 @@
               '</div>';
           } else {
             card.innerHTML =
-              '<div class="node-name">'+(n.online?'🟢':'🔴')+' '+esc(n.name)+'</div>'+
+              '<div style="display:flex;justify-content:space-between;align-items:flex-start">'+
+                '<div class="node-name">'+(n.online?'🟢':'🔴')+' '+esc(n.name)+'</div>'+
+                '<span class="latency-val" style="font-size:.7rem;color:var(--text-dim);flex-shrink:0">⏱ —</span>'+
+              '</div>'+
               (sysInfo.trim() ? '<div class="node-sys">'+esc(sysInfo)+'</div>' : '')+
               '<div class="node-url">'+esc(n.url||'')+'</div>'+
               (n.notes ? '<div class="node-notes">📝 '+esc(n.notes)+'</div>' : '')+
@@ -342,6 +346,17 @@
           sysEl.textContent = si2;
         } else if (sysEl) { sysEl.remove(); }
 
+        // 延迟 (横版: col-left底部 / 网格: 右上角)
+        var latEl = card.querySelector('.node-latency') || card.querySelector('.latency-val');
+        if (latEl && n.latency_ms > 0) {
+          var ms = n.latency_ms;
+          latEl.textContent = '⏱ ' + (ms < 1000 ? ms + 'ms' : (ms/1000).toFixed(1)+'s');
+          latEl.style.color = ms < 100 ? 'var(--success)' : ms < 500 ? 'var(--warning,#e0af68)' : 'var(--error)';
+        } else if (latEl && n.online === false) {
+          latEl.textContent = '⏱ —';
+          latEl.style.color = 'var(--text-dim)';
+        }
+
         var body = isRow ? card.querySelector('.col-right-stack') : card.querySelector('.metrics-body');
         if (!body) return;