Varaverk: monitor grid overhaul + Containers & VMs card

Monitor layout (8-col grid):
- Row 1: System | Power | CPU | Memory | Network
- Row 2: Scripts | Partner & Fallback (span 3) | Containers & VMs (span 4)
- Row 3: GPU (span 2) | Transcode (span 2) | Streams (span 4)
- Row 4: Parity (cols 1-2) | Pools (cols 3-4) | Array (cols 5-8)

New Containers & VMs card:
- Reads FolderView3 folders from docker.json; expand/collapse per folder
- VMs listed first (virsh); containers show start/stop/webui/edit actions
- 2-column balanced layout; collapses to 1 column below 900px
- Docker WebUI URLs resolved from dockerMan template XMLs

New files: include/vms.php, include/docker_folders.php, api/docker_action.php, api/snapshot.php
Responsive: explicit grid-column placements reset at 1024px breakpoint

Plugin/usr/local/emhttp/plugins/varaverk/api/docker_action.php

@@ -0,0 +1,21 @@
+<?php
+header('Content-Type: application/json');
+
+$action = trim($_POST['action'] ?? '');
+$name   = trim($_POST['name']   ?? '');
+
+if (!$name || !in_array($action, ['start', 'stop'], true)) {
+    echo json_encode(['ok' => false, 'error' => 'Invalid request']);
+    exit;
+}
+
+// Confirm container exists
+$check = trim(shell_exec('docker ps -a --filter ' . escapeshellarg('name=^' . $name . '$') . " --format '{{.Names}}' 2>/dev/null") ?? '');
+if ($check !== $name) {
+    echo json_encode(['ok' => false, 'error' => 'Container not found']);
+    exit;
+}
+
+exec(($action === 'start' ? 'docker start' : 'docker stop') . ' ' . escapeshellarg($name) . ' 2>&1', $out, $rc);
+
+echo json_encode(['ok' => $rc === 0, 'output' => implode("\n", $out)]);