Group dashboard targets into a collapsible Targets section with Running/Stopped subsections

Wrap running and stopped target lists under a parent Targets group.
Fix narrow-screen layout by keeping action buttons inline and hiding
metrics below 768px.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/src/wled_controller/static/style.css

@@ -3276,6 +3276,14 @@ input:-webkit-autofill:focus {
     font-weight: 600;
 }
 
+.dashboard-subsection {
+    margin-bottom: 10px;
+    padding-left: 16px;
+}
+.dashboard-subsection .dashboard-section-header {
+    font-size: 0.72rem;
+}
+
 .dashboard-stop-all {
     margin-left: auto;
     padding: 2px 8px;
@@ -3454,12 +3462,12 @@ input:-webkit-autofill:focus {
 
 @media (max-width: 768px) {
     .dashboard-target {
-        grid-template-columns: 1fr;
+        grid-template-columns: 1fr auto;
         gap: 6px;
     }
 
-    .dashboard-target-actions {
-        justify-content: flex-end;
+    .dashboard-target-metrics {
+        display: none;
     }
 }