feat: Proxmox nested nodes — VM/LXC rendered inside resizable group container

- ProxmoxGroupNode: resizable bordered container with orange accent, header
  bar (icon, label, IP, status dot), NodeResizer on selection
- nodeTypes: proxmox now uses ProxmoxGroupNode instead of BaseNode
- NodeData: added parent_id field
- canvasStore: addNode and loadCanvas wire parentId + extent='parent'
  for child nodes; loadCanvas sorts parents before children (RF requirement)
- NodeModal: Parent Proxmox dropdown appears when type is VM or LXC,
  lists all Proxmox nodes on the canvas
- App.tsx: passes proxmoxNodes to modals; child nodes positioned relative
  to parent (x:20, y:50); Proxmox nodes get width:300/height:200 on load
- layout.ts: Dagre skips child nodes (parentId set); uses actual group
  dimensions for Proxmox nodes in rank calculation

frontend/src/components/canvas/nodes/ProxmoxGroupNode.tsx

@@ -0,0 +1,72 @@
+import { Handle, Position, NodeResizer, type NodeProps, type Node } from '@xyflow/react'
+import { Layers } from 'lucide-react'
+import type { NodeData, NodeStatus } from '@/types'
+
+const STATUS_COLORS: Record<NodeStatus, string> = {
+  online: '#39d353',
+  offline: '#f85149',
+  pending: '#e3b341',
+  unknown: '#8b949e',
+}
+
+const GLOW = '#ff6e00'
+
+export function ProxmoxGroupNode({ data, selected }: NodeProps<Node<NodeData>>) {
+  const statusColor = STATUS_COLORS[data.status]
+  const isOnline = data.status === 'online'
+
+  return (
+    <>
+      <NodeResizer
+        minWidth={220}
+        minHeight={160}
+        isVisible={selected}
+        lineStyle={{ borderColor: GLOW, opacity: 0.6 }}
+        handleStyle={{ borderColor: GLOW, backgroundColor: '#21262d' }}
+      />
+
+      {/* Group border */}
+      <div
+        className="w-full h-full rounded-xl border-2 flex flex-col overflow-hidden"
+        style={{
+          borderColor: selected ? GLOW : isOnline ? `${GLOW}66` : '#30363d',
+          background: isOnline ? `${GLOW}08` : '#0d111766',
+          boxShadow: isOnline
+            ? `0 0 20px ${GLOW}1a, inset 0 0 40px ${GLOW}08`
+            : selected
+            ? `0 0 12px ${GLOW}33`
+            : 'none',
+        }}
+      >
+        {/* Header bar */}
+        <div
+          className="flex items-center gap-2 px-2.5 py-1.5 shrink-0"
+          style={{ background: isOnline ? `${GLOW}18` : '#161b2288', borderBottom: `1px solid ${isOnline ? `${GLOW}33` : '#30363d'}` }}
+        >
+          <div
+            className="flex items-center justify-center w-5 h-5 rounded-md shrink-0"
+            style={{ color: isOnline ? GLOW : '#8b949e', background: '#161b22' }}
+          >
+            <Layers size={12} />
+          </div>
+          <div className="flex flex-col min-w-0 flex-1">
+            <span className="text-[11px] font-semibold leading-tight truncate" style={{ color: isOnline ? GLOW : '#c9d1d9' }}>
+              {data.label}
+            </span>
+            {data.ip && (
+              <span className="font-mono text-[9px] text-[#8b949e] truncate">{data.ip}</span>
+            )}
+          </div>
+          {/* Status dot */}
+          <div className="w-1.5 h-1.5 rounded-full shrink-0" style={{ backgroundColor: statusColor }} title={data.status} />
+        </div>
+
+        {/* Inner area — React Flow places children here */}
+        <div className="flex-1 relative" />
+      </div>
+
+      <Handle type="target" position={Position.Top} className="!bg-[#30363d] !border-[#8b949e]" />
+      <Handle type="source" position={Position.Bottom} className="!bg-[#30363d] !border-[#8b949e]" />
+    </>
+  )
+}

frontend/src/components/canvas/nodes/nodeTypes.ts

@@ -1,11 +1,12 @@
-import { IspNode, RouterNode, SwitchNode, ServerNode, ProxmoxNode, VmNode, LxcNode, NasNode, IotNode, ApNode, GenericNode } from './index'
+import { IspNode, RouterNode, SwitchNode, ServerNode, VmNode, LxcNode, NasNode, IotNode, ApNode, GenericNode } from './index'
+import { ProxmoxGroupNode } from './ProxmoxGroupNode'
 
 export const nodeTypes = {
   isp: IspNode,
   router: RouterNode,
   switch: SwitchNode,
   server: ServerNode,
-  proxmox: ProxmoxNode,
+  proxmox: ProxmoxGroupNode,
   vm: VmNode,
   lxc: LxcNode,
   nas: NasNode,