feat: drag-to-resize device nodes + BrickWallFire for firewall

- NodeResizer on DeviceNode (same pattern as group nodes); icon scales
  proportionally with node width, clamped 16–60px
- Removes S/M/L static picker — resize is now direct manipulation
- firewall: ShieldAlert → BrickWallFire

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

frontend/src/components/network/panels/PropertiesPanel.tsx

@@ -3,7 +3,7 @@ import { Trash2, Minus, Spline, GitBranch, BringToFront, SendToBack } from 'luci
 import { cn } from '@/lib/utils'
 import type { DeviceProperties, DiagramEdge } from '@/types'
 import type { Node, Edge } from '@xyflow/react'
-import type { DeviceNodeData, IconSize } from '../nodes/DeviceNode'
+import type { DeviceNodeData } from '../nodes/DeviceNode'
 
 interface PropertiesPanelProps {
   selectedNode: Node | null
@@ -272,30 +272,6 @@ export function PropertiesPanel({
           <FieldInput value={nodeData.label} onChange={handleLabelChange} placeholder="Device name" />
         </div>
 
-        {/* Icon size */}
-        <div className="flex flex-col gap-1">
-          <FieldLabel>Icon Size</FieldLabel>
-          <div className="flex gap-1">
-            {(['sm', 'md', 'lg'] as IconSize[]).map(size => {
-              const active = (nodeData.iconSize ?? 'md') === size
-              return (
-                <button
-                  key={size}
-                  onClick={() => onNodeUpdate(selectedNode!.id, { iconSize: size } as Partial<DeviceNodeData>)}
-                  className={cn(
-                    'flex flex-1 items-center justify-center rounded border py-1.5 text-[10px] font-medium uppercase transition-colors',
-                    active
-                      ? 'border-accent bg-accent/10 text-accent'
-                      : 'border-default text-muted-foreground hover:border-hover hover:text-primary',
-                  )}
-                >
-                  {size}
-                </button>
-              )
-            })}
-          </div>
-        </div>
-
         {/* Layering */}
         <div className="flex flex-col gap-1">
           <FieldLabel>Layer</FieldLabel>