feat: add hardware specs to nodes (CPU, RAM, Disk) with canvas display

- Add cpu_count, cpu_model, ram_gb, disk_gb, show_hardware fields to NodeData
- NodeModal: collapsible Hardware section with toggle to show specs on canvas
- BaseNode: 2-line hardware section with Cpu/MemoryStick/HardDrive icons, only renders set fields
- DetailPanel: Hardware section with GB/TB formatting
- Backend: schema, model, DB migration, canvas save/load support
- Tests: frontend (NodeModal, DetailPanel) + backend (canvas persist/load)

frontend/src/components/panels/DetailPanel.tsx

@@ -100,6 +100,17 @@ export function DetailPanel({ onEdit }: DetailPanelProps) {
         )}
       </div>
 
+      {/* Hardware */}
+      {(data.cpu_count != null || data.cpu_model || data.ram_gb != null || data.disk_gb != null) && (
+        <div className="flex flex-col gap-3 px-4 py-3 text-sm border-t border-border">
+          <span className="text-[10px] font-semibold uppercase tracking-wider text-muted-foreground/50">Hardware</span>
+          {data.cpu_model && <DetailRow label="CPU" value={data.cpu_model} />}
+          {data.cpu_count != null && <DetailRow label="Cores" value={String(data.cpu_count)} mono />}
+          {data.ram_gb != null && <DetailRow label="RAM" value={formatStorage(data.ram_gb)} mono />}
+          {data.disk_gb != null && <DetailRow label="Disk" value={formatStorage(data.disk_gb)} mono />}
+        </div>
+      )}
+
       {/* Services */}
       <div className="px-4 py-3 border-t border-border">
         <div className="flex items-center justify-between mb-2">
@@ -202,6 +213,11 @@ export function DetailPanel({ onEdit }: DetailPanelProps) {
   )
 }
 
+function formatStorage(gb: number): string {
+  if (gb >= 1024) return `${(gb / 1024).toFixed(1).replace(/\.0$/, '')} TB`
+  return `${gb} GB`
+}
+
 function DetailRow({ label, value, mono }: { label: string; value: string; mono?: boolean }) {
   return (
     <div className="flex justify-between gap-2 items-baseline">

frontend/src/components/panels/__tests__/DetailPanel.test.tsx

@@ -0,0 +1,118 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest'
+import { render, screen } from '@testing-library/react'
+import { DetailPanel } from '../DetailPanel'
+import * as canvasStore from '@/stores/canvasStore'
+import type { NodeData } from '@/types'
+import type { Node } from '@xyflow/react'
+
+vi.mock('@/stores/canvasStore')
+
+function makeNode(data: Partial<NodeData>): Node<NodeData> {
+  return {
+    id: 'n1',
+    type: data.type ?? 'server',
+    position: { x: 0, y: 0 },
+    data: {
+      label: 'Test Node',
+      type: 'server',
+      status: 'online',
+      services: [],
+      ...data,
+    },
+  }
+}
+
+function setupStore(nodeData: Partial<NodeData> = {}) {
+  vi.mocked(canvasStore.useCanvasStore).mockReturnValue({
+    nodes: [makeNode(nodeData)],
+    selectedNodeId: 'n1',
+    setSelectedNode: vi.fn(),
+    deleteNode: vi.fn(),
+    updateNode: vi.fn(),
+  } as unknown as ReturnType<typeof canvasStore.useCanvasStore>)
+}
+
+describe('DetailPanel', () => {
+  beforeEach(() => {
+    vi.mocked(canvasStore.useCanvasStore).mockReturnValue({
+      nodes: [],
+      selectedNodeId: null,
+      setSelectedNode: vi.fn(),
+      deleteNode: vi.fn(),
+      updateNode: vi.fn(),
+    } as unknown as ReturnType<typeof canvasStore.useCanvasStore>)
+  })
+
+  it('renders nothing when no node is selected', () => {
+    const { container } = render(<DetailPanel onEdit={vi.fn()} />)
+    expect(container.firstChild).toBeNull()
+  })
+
+  it('renders node label and status', () => {
+    setupStore({ label: 'My Server', status: 'online' })
+    render(<DetailPanel onEdit={vi.fn()} />)
+    expect(screen.getByText('My Server')).toBeDefined()
+    expect(screen.getByText('online')).toBeDefined()
+  })
+
+  it('renders nothing for groupRect nodes', () => {
+    setupStore({ type: 'groupRect', label: 'Zone' })
+    const { container } = render(<DetailPanel onEdit={vi.fn()} />)
+    expect(container.firstChild).toBeNull()
+  })
+
+  describe('Hardware section', () => {
+    it('does not render hardware section when no hardware data', () => {
+      setupStore({ label: 'Server' })
+      render(<DetailPanel onEdit={vi.fn()} />)
+      expect(screen.queryByText('Hardware')).toBeNull()
+    })
+
+    it('renders hardware section when cpu_count is set', () => {
+      setupStore({ cpu_count: 8 })
+      render(<DetailPanel onEdit={vi.fn()} />)
+      expect(screen.getByText('Hardware')).toBeDefined()
+      expect(screen.getByText('8')).toBeDefined()
+    })
+
+    it('renders cpu_model', () => {
+      setupStore({ cpu_model: 'Intel Xeon E5-2680' })
+      render(<DetailPanel onEdit={vi.fn()} />)
+      expect(screen.getByText('Intel Xeon E5-2680')).toBeDefined()
+    })
+
+    it('formats ram_gb in GB', () => {
+      setupStore({ ram_gb: 32 })
+      render(<DetailPanel onEdit={vi.fn()} />)
+      expect(screen.getByText('32 GB')).toBeDefined()
+    })
+
+    it('formats ram_gb >= 1024 as TB', () => {
+      setupStore({ ram_gb: 2048 })
+      render(<DetailPanel onEdit={vi.fn()} />)
+      expect(screen.getByText('2 TB')).toBeDefined()
+    })
+
+    it('formats disk_gb in GB', () => {
+      setupStore({ disk_gb: 500 })
+      render(<DetailPanel onEdit={vi.fn()} />)
+      expect(screen.getByText('500 GB')).toBeDefined()
+    })
+
+    it('formats disk_gb >= 1024 as TB', () => {
+      setupStore({ disk_gb: 1536 })
+      render(<DetailPanel onEdit={vi.fn()} />)
+      expect(screen.getByText('1.5 TB')).toBeDefined()
+    })
+
+    it('renders all hardware fields together', () => {
+      setupStore({ cpu_count: 16, cpu_model: 'AMD EPYC', ram_gb: 128, disk_gb: 4096 })
+      render(<DetailPanel onEdit={vi.fn()} />)
+      expect(screen.getByText('Hardware')).toBeDefined()
+      expect(screen.getByText('AMD EPYC')).toBeDefined()
+      expect(screen.getByText('16')).toBeDefined()
+      expect(screen.getByText('128 GB')).toBeDefined()
+      expect(screen.getByText('4 TB')).toBeDefined()
+    })
+  })
+})