feat: edge edit mode + proxmox container mode toggle

- Double-click any link to open Edit Link modal (type, label, VLAN ID, delete)
- Add updateEdge / deleteEdge actions to canvasStore
- Add container_mode field to proxmox nodes (backend model, schemas, migration)
- NodeModal shows container toggle for proxmox type (defaults ON)
- ProxmoxGroupNode renders as regular BaseNode when container_mode is OFF
- setProxmoxContainerMode store action handles structural changes atomically
  (children parentId/extent, node dimensions)
- CanvasContainer filters edges between container proxmox and its children
- Canvas load respects container_mode when assigning parentId/extent

frontend/src/components/canvas/CanvasContainer.tsx

@@ -1,4 +1,4 @@
-import { useCallback } from 'react'
+import { useCallback, useMemo } from 'react'
 import {
   ReactFlow,
   Background,
@@ -17,9 +17,10 @@ import type { NodeData, EdgeData } from '@/types'
 
 interface CanvasContainerProps {
   onConnect?: (connection: Connection) => void
+  onEdgeDoubleClick?: (edge: Edge<EdgeData>) => void
 }
 
-export function CanvasContainer({ onConnect: onConnectProp }: CanvasContainerProps) {
+export function CanvasContainer({ onConnect: onConnectProp, onEdgeDoubleClick }: CanvasContainerProps) {
   const {
     nodes, edges,
     onNodesChange, onEdgesChange,
@@ -34,16 +35,38 @@ export function CanvasContainer({ onConnect: onConnectProp }: CanvasContainerPro
     setSelectedNode(null)
   }, [setSelectedNode])
 
+  const handleEdgeDoubleClick = useCallback((_: React.MouseEvent, edge: Edge<EdgeData>) => {
+    onEdgeDoubleClick?.(edge)
+  }, [onEdgeDoubleClick])
+
+  // Hide edges between a container-mode proxmox and its direct children
+  const visibleEdges = useMemo(() => {
+    const containerIds = new Set(
+      nodes
+        .filter((n) => n.type === 'proxmox' && n.data.container_mode !== false)
+        .map((n) => n.id)
+    )
+    const childParentMap = new Map(
+      nodes.filter((n) => n.data.parent_id).map((n) => [n.id, n.data.parent_id as string])
+    )
+    return (edges as Edge<EdgeData>[]).filter((e) => {
+      if (containerIds.has(e.source) && childParentMap.get(e.target) === e.source) return false
+      if (containerIds.has(e.target) && childParentMap.get(e.source) === e.target) return false
+      return true
+    })
+  }, [nodes, edges])
+
   return (
     <div className="w-full h-full">
       <ReactFlow
         nodes={nodes}
-        edges={edges as Edge<EdgeData>[]}
+        edges={visibleEdges}
         onNodesChange={onNodesChange}
         onEdgesChange={onEdgesChange}
         onConnect={onConnectProp}
         onNodeClick={onNodeClick}
         onPaneClick={onPaneClick}
+        onEdgeDoubleClick={handleEdgeDoubleClick}
         nodeTypes={nodeTypes}
         edgeTypes={edgeTypes}
         snapToGrid

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

@@ -1,6 +1,7 @@
 import { Handle, Position, NodeResizer, type NodeProps, type Node } from '@xyflow/react'
 import { Layers } from 'lucide-react'
 import type { NodeData, NodeStatus } from '@/types'
+import { BaseNode } from './BaseNode'
 
 const STATUS_COLORS: Record<NodeStatus, string> = {
   online: '#39d353',
@@ -11,7 +12,14 @@ const STATUS_COLORS: Record<NodeStatus, string> = {
 
 const GLOW = '#ff6e00'
 
-export function ProxmoxGroupNode({ data, selected }: NodeProps<Node<NodeData>>) {
+export function ProxmoxGroupNode(props: NodeProps<Node<NodeData>>) {
+  const { data, selected } = props
+
+  // Render as a regular node when container mode is disabled
+  if (data.container_mode === false) {
+    return <BaseNode {...props} icon={Layers} glowColor={GLOW} />
+  }
+
   const statusColor = STATUS_COLORS[data.status]
   const isOnline = data.status === 'online'