Add dashboard tab with real-time target status overview

Dashboard is the new default tab showing running/stopped targets
with FPS, uptime, errors metrics. Updates live via events WebSocket.
Includes Stop All button and Start/Stop per target.

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

server/src/wled_controller/static/style.css

@@ -3105,3 +3105,151 @@ input:-webkit-autofill:focus {
     flex: 0 0 24px;
 }
 
+/* ── Dashboard ── */
+
+.dashboard-section {
+    margin-bottom: 24px;
+}
+
+.dashboard-section-header {
+    font-size: 1rem;
+    font-weight: 600;
+    margin-bottom: 10px;
+    color: var(--text-secondary);
+    display: flex;
+    align-items: center;
+    gap: 8px;
+}
+
+.dashboard-section-count {
+    background: var(--border-color);
+    color: var(--text-secondary);
+    border-radius: 10px;
+    padding: 1px 8px;
+    font-size: 0.8rem;
+    font-weight: 600;
+}
+
+.dashboard-stop-all {
+    margin-left: auto;
+    padding: 3px 10px;
+    font-size: 0.75rem;
+    white-space: nowrap;
+    flex: 0 0 auto;
+}
+
+.dashboard-target {
+    display: grid;
+    grid-template-columns: 1fr auto auto;
+    align-items: center;
+    gap: 16px;
+    padding: 12px 16px;
+    background: var(--card-bg);
+    border: 1px solid var(--border-color);
+    border-radius: 8px;
+    margin-bottom: 8px;
+}
+
+.dashboard-target-info {
+    display: flex;
+    align-items: center;
+    gap: 8px;
+    min-width: 0;
+    overflow: hidden;
+}
+
+.dashboard-target-icon {
+    font-size: 1.2rem;
+    flex-shrink: 0;
+}
+
+.dashboard-target-name {
+    font-weight: 600;
+    white-space: nowrap;
+    overflow: hidden;
+    text-overflow: ellipsis;
+    display: flex;
+    align-items: center;
+    gap: 6px;
+}
+
+.dashboard-target-name .health-dot {
+    margin-right: 0;
+    flex-shrink: 0;
+}
+
+.dashboard-target-subtitle {
+    font-size: 0.75rem;
+    color: var(--text-secondary);
+    white-space: nowrap;
+    overflow: hidden;
+    text-overflow: ellipsis;
+}
+
+.dashboard-target-metrics {
+    display: grid;
+    grid-template-columns: 90px 80px 60px;
+    gap: 12px;
+    align-items: center;
+}
+
+.dashboard-metric {
+    text-align: center;
+}
+
+.dashboard-metric-value {
+    font-size: 1.05rem;
+    font-weight: 700;
+    color: var(--primary-color);
+}
+
+.dashboard-metric-label {
+    font-size: 0.7rem;
+    color: var(--text-secondary);
+    text-transform: uppercase;
+    letter-spacing: 0.3px;
+}
+
+.dashboard-target-actions {
+    display: flex;
+    align-items: center;
+    gap: 8px;
+}
+
+.dashboard-status-dot {
+    font-size: 1.2rem;
+    line-height: 1;
+}
+
+.dashboard-status-dot.active {
+    color: #4CAF50;
+    animation: pulse 2s infinite;
+}
+
+.dashboard-no-targets {
+    text-align: center;
+    padding: 40px 20px;
+    color: var(--text-secondary);
+    font-size: 1rem;
+}
+
+.dashboard-badge-stopped {
+    padding: 3px 10px;
+    border-radius: 10px;
+    font-size: 0.75rem;
+    font-weight: 600;
+    background: var(--border-color);
+    color: var(--text-secondary);
+}
+
+@media (max-width: 768px) {
+    .dashboard-target {
+        grid-template-columns: 1fr;
+        gap: 10px;
+    }
+
+    .dashboard-target-actions {
+        justify-content: flex-end;
+    }
+}
+