chore: bump version to 1.6.0

fix: DEL key deletes nodes and deletion is undoable

backend/app/api/routes/scan.py

@@ -17,7 +17,6 @@ from app.services.scanner import run_scan
 
 class ScanConfig(BaseModel):
     ranges: list[str]
-    interval_seconds: int
 
 
 logger = logging.getLogger(__name__)
@@ -103,17 +102,13 @@ async def list_runs(db: AsyncSession = Depends(get_db), _: str = Depends(get_cur
 
 @router.get("/config", response_model=ScanConfig)
 async def get_scan_config(_: str = Depends(get_current_user)) -> ScanConfig:
-    return ScanConfig(
+    return ScanConfig(ranges=settings.scanner_ranges)
-        ranges=settings.scanner_ranges,
-        interval_seconds=settings.status_checker_interval,
-    )
 
 
 @router.post("/config", response_model=ScanConfig)
 async def update_scan_config(payload: ScanConfig, _: str = Depends(get_current_user)) -> ScanConfig:
     try:
         settings.scanner_ranges = payload.ranges
-        settings.status_checker_interval = payload.interval_seconds
         settings.save_overrides()
         return payload
     except Exception as exc:

backend/app/api/routes/settings.py

@@ -0,0 +1,29 @@
+"""App-level settings (status checker interval, etc.)."""
+from fastapi import APIRouter, Depends, HTTPException
+from pydantic import BaseModel
+
+from app.api.deps import get_current_user
+from app.core.config import settings
+
+router = APIRouter()
+
+
+class AppSettings(BaseModel):
+    interval_seconds: int
+
+
+@router.get("", response_model=AppSettings)
+async def get_settings(_: str = Depends(get_current_user)) -> AppSettings:
+    return AppSettings(interval_seconds=settings.status_checker_interval)
+
+
+@router.post("", response_model=AppSettings)
+async def update_settings(
+    payload: AppSettings, _: str = Depends(get_current_user)
+) -> AppSettings:
+    try:
+        settings.status_checker_interval = payload.interval_seconds
+        settings.save_overrides()
+        return payload
+    except Exception as exc:
+        raise HTTPException(status_code=500, detail=str(exc)) from exc

backend/app/core/scheduler.py

@@ -47,11 +47,23 @@ async def _run_status_checks() -> None:
 
 def start_scheduler() -> None:
     global scheduler
+    if scheduler.running:
+        scheduler.shutdown(wait=False)
     scheduler = AsyncIOScheduler()
     scheduler.add_job(_run_status_checks, "interval", seconds=settings.status_checker_interval, id="status_checks")
     scheduler.start()
     logger.info("Scheduler started — status checks every %ds", settings.status_checker_interval)
 
 
+def reschedule_status_checks(interval_seconds: int) -> None:
+    """Update the status check interval on the running scheduler."""
+    if not scheduler.running:
+        logger.warning("Scheduler not running, skipping reschedule")
+        return
+    scheduler.reschedule_job("status_checks", trigger="interval", seconds=interval_seconds)
+    logger.info("Status checks rescheduled to every %ds", interval_seconds)
+
+
 def stop_scheduler() -> None:
-    scheduler.shutdown(wait=False)
+    if scheduler.running:
+        scheduler.shutdown(wait=False)

backend/app/main.py

@@ -6,6 +6,7 @@ from fastapi import FastAPI
 from fastapi.middleware.cors import CORSMiddleware
 
 from app.api.routes import auth, canvas, edges, liveview, nodes, scan, status
+from app.api.routes import settings as settings_routes
 from app.core.config import settings
 from app.core.scheduler import start_scheduler, stop_scheduler
 from app.db.database import init_db
@@ -40,6 +41,7 @@ app.include_router(edges.router, prefix="/api/v1/edges", tags=["edges"])
 app.include_router(canvas.router, prefix="/api/v1/canvas", tags=["canvas"])
 app.include_router(scan.router, prefix="/api/v1/scan", tags=["scan"])
 app.include_router(status.router, prefix="/api/v1/status", tags=["status"])
+app.include_router(settings_routes.router, prefix="/api/v1/settings", tags=["settings"])
 app.include_router(liveview.router, prefix="/api/v1/liveview", tags=["liveview"])
 
 

backend/app/services/scanner.py

@@ -7,7 +7,7 @@ from typing import Any
 
 from sqlalchemy.ext.asyncio import AsyncSession
 
-from app.db.models import PendingDevice, ScanRun
+from app.db.models import Node, PendingDevice, ScanRun
 from app.services.fingerprint import fingerprint_ports, suggest_node_type
 
 logger = logging.getLogger(__name__)
@@ -107,18 +107,54 @@ async def run_scan(ranges: list[str], db: AsyncSession, run_id: str) -> None:
 
     devices_found = 0
     try:
+        # Clean up stale pending devices whose IPs are already in the canvas
+        # (covers devices approved between scans, or pre-existing canvas nodes)
+        canvas_ips_result = await db.execute(select(Node.ip).where(Node.ip.isnot(None)))
+        canvas_ips = {row[0] for row in canvas_ips_result.fetchall()}
+        if canvas_ips:
+            stale_result = await db.execute(
+                select(PendingDevice).where(
+                    PendingDevice.status == "pending",
+                    PendingDevice.ip.in_(canvas_ips),
+                )
+            )
+            for stale in stale_result.scalars().all():
+                await db.delete(stale)
+            await db.commit()
+
         for cidr in ranges:
             # Run nmap in a thread pool — does not block the event loop
             hosts = await asyncio.to_thread(_nmap_scan, cidr)
 
             for host in hosts:
+                ip = host["ip"]
+
+                # Skip if device is already in the canvas (approved node)
+                canvas_result = await db.execute(
+                    select(Node).where(Node.ip == ip)
+                )
+                if canvas_result.scalar_one_or_none() is not None:
+                    logger.debug("Skipping %s — already in canvas", ip)
+                    continue
+
+                # Skip if device was explicitly hidden by the user
+                hidden_result = await db.execute(
+                    select(PendingDevice).where(
+                        PendingDevice.ip == ip,
+                        PendingDevice.status == "hidden",
+                    )
+                )
+                if hidden_result.scalar_one_or_none() is not None:
+                    logger.debug("Skipping %s — hidden by user", ip)
+                    continue
+
                 services = fingerprint_ports(host["open_ports"])
                 suggested_type = suggest_node_type(host["open_ports"], host.get("mac"))
 
                 # Update existing pending device or create a new one
                 existing_result = await db.execute(
                     select(PendingDevice).where(
-                        PendingDevice.ip == host["ip"],
+                        PendingDevice.ip == ip,
                         PendingDevice.status == "pending",
                     )
                 )
@@ -131,7 +167,7 @@ async def run_scan(ranges: list[str], db: AsyncSession, run_id: str) -> None:
                     existing.suggested_type = suggested_type
                 else:
                     device = PendingDevice(
-                        ip=host["ip"],
+                        ip=ip,
                         mac=host.get("mac"),
                         hostname=host.get("hostname"),
                         os=host.get("os"),

backend/tests/test_scan.py

@@ -7,7 +7,7 @@ from httpx import AsyncClient
 from sqlalchemy import select
 from sqlalchemy.ext.asyncio import AsyncSession
 
-from app.db.models import PendingDevice, ScanRun
+from app.db.models import Node, PendingDevice, ScanRun
 from app.services.scanner import run_scan
 
 
@@ -199,6 +199,119 @@ async def test_run_scan_creates_new_pending_device(db_session: AsyncSession):
     assert device.suggested_type == "server"
 
 
+@pytest.mark.asyncio
+async def test_run_scan_purges_stale_pending_for_canvas_nodes(db_session: AsyncSession):
+    """Pending devices that were already in canvas before scan starts must be removed."""
+    node = Node(
+        id=str(uuid.uuid4()),
+        label="Existing Server",
+        type="server",
+        ip="192.168.1.50",
+        status="online",
+        services=[],
+        pos_x=0.0,
+        pos_y=0.0,
+    )
+    stale = PendingDevice(
+        id=str(uuid.uuid4()),
+        ip="192.168.1.50",
+        mac=None,
+        hostname=None,
+        os=None,
+        services=[],
+        suggested_type="generic",
+        status="pending",
+    )
+    db_session.add(node)
+    db_session.add(stale)
+    await db_session.commit()
+
+    run_id = str(uuid.uuid4())
+    run = ScanRun(id=run_id, status="running", ranges=["192.168.1.0/24"])
+    db_session.add(run)
+    await db_session.commit()
+
+    with (
+        patch("app.services.scanner._nmap_scan", return_value=[]),
+        patch("app.api.routes.status.broadcast_scan_update", new_callable=AsyncMock),
+    ):
+        await run_scan(["192.168.1.0/24"], db_session, run_id)
+
+    result = await db_session.execute(
+        select(PendingDevice).where(PendingDevice.ip == "192.168.1.50")
+    )
+    assert result.scalar_one_or_none() is None
+
+
+@pytest.mark.asyncio
+async def test_run_scan_skips_ip_already_in_canvas(db_session: AsyncSession):
+    """Devices whose IP already exists as a canvas Node must not appear in pending."""
+    node = Node(
+        id=str(uuid.uuid4()),
+        label="Existing Server",
+        type="server",
+        ip="192.168.1.50",
+        status="online",
+        services=[],
+        pos_x=0.0,
+        pos_y=0.0,
+    )
+    db_session.add(node)
+    await db_session.commit()
+
+    run_id = str(uuid.uuid4())
+    run = ScanRun(id=run_id, status="running", ranges=["192.168.1.0/24"])
+    db_session.add(run)
+    await db_session.commit()
+
+    with (
+        patch("app.services.scanner._nmap_scan", return_value=[MOCK_HOST]),
+        patch("app.api.routes.status.broadcast_scan_update", new_callable=AsyncMock),
+    ):
+        await run_scan(["192.168.1.0/24"], db_session, run_id)
+
+    result = await db_session.execute(
+        select(PendingDevice).where(PendingDevice.ip == "192.168.1.50")
+    )
+    assert result.scalar_one_or_none() is None
+
+
+@pytest.mark.asyncio
+async def test_run_scan_skips_hidden_device(db_session: AsyncSession):
+    """Devices previously hidden by the user must not re-appear in pending on re-scan."""
+    hidden = PendingDevice(
+        id=str(uuid.uuid4()),
+        ip="192.168.1.50",
+        mac=None,
+        hostname=None,
+        os=None,
+        services=[],
+        suggested_type="generic",
+        status="hidden",
+    )
+    db_session.add(hidden)
+    await db_session.commit()
+
+    run_id = str(uuid.uuid4())
+    run = ScanRun(id=run_id, status="running", ranges=["192.168.1.0/24"])
+    db_session.add(run)
+    await db_session.commit()
+
+    with (
+        patch("app.services.scanner._nmap_scan", return_value=[MOCK_HOST]),
+        patch("app.api.routes.status.broadcast_scan_update", new_callable=AsyncMock),
+    ):
+        await run_scan(["192.168.1.0/24"], db_session, run_id)
+
+    result = await db_session.execute(
+        select(PendingDevice).where(
+            PendingDevice.ip == "192.168.1.50",
+            PendingDevice.status == "pending",
+        )
+    )
+    assert result.scalar_one_or_none() is None
+
+
 @pytest.mark.asyncio
 async def test_run_scan_updates_existing_pending_device(db_session: AsyncSession):
     """Re-scanning the same IP updates services instead of creating a duplicate."""

backend/tests/test_settings.py

@@ -0,0 +1,47 @@
+"""Tests for GET/POST /api/v1/settings."""
+from unittest.mock import patch
+
+import pytest
+from httpx import AsyncClient
+
+
+@pytest.fixture
+async def headers(client: AsyncClient):
+    res = await client.post("/api/v1/auth/login", json={"username": "admin", "password": "admin"})
+    token = res.json()["access_token"]
+    return {"Authorization": f"Bearer {token}"}
+
+
+@pytest.mark.asyncio
+async def test_get_settings_requires_auth(client: AsyncClient):
+    res = await client.get("/api/v1/settings")
+    assert res.status_code == 401
+
+
+@pytest.mark.asyncio
+async def test_get_settings_returns_interval(client: AsyncClient, headers):
+    res = await client.get("/api/v1/settings", headers=headers)
+    assert res.status_code == 200
+    data = res.json()
+    assert "interval_seconds" in data
+    assert isinstance(data["interval_seconds"], int)
+
+
+@pytest.mark.asyncio
+async def test_update_settings_saves_interval(client: AsyncClient, headers):
+    with patch("app.api.routes.settings.settings") as mock_settings:
+        mock_settings.status_checker_interval = 60
+        mock_settings.save_overrides = lambda: None
+        res = await client.post(
+            "/api/v1/settings",
+            json={"interval_seconds": 120},
+            headers=headers,
+        )
+    assert res.status_code == 200
+    assert res.json()["interval_seconds"] == 120
+
+
+@pytest.mark.asyncio
+async def test_update_settings_requires_auth(client: AsyncClient):
+    res = await client.post("/api/v1/settings", json={"interval_seconds": 30})
+    assert res.status_code == 401

frontend/package.json

@@ -1,7 +1,7 @@
 {
   "name": "frontend",
   "private": true,
-  "version": "1.5.0",
+  "version": "1.6.0",
   "type": "module",
   "scripts": {
     "dev": "vite",

frontend/src/api/client.ts

@@ -59,6 +59,11 @@ export const scanApi = {
   approve: (id: string, nodeData: object) => api.post(`/scan/pending/${id}/approve`, nodeData),
   hide: (id: string) => api.post(`/scan/pending/${id}/hide`),
   ignore: (id: string) => api.post(`/scan/pending/${id}/ignore`),
-  getConfig: () => api.get<{ ranges: string[]; interval_seconds: number }>('/scan/config'),
+  getConfig: () => api.get<{ ranges: string[] }>('/scan/config'),
-  saveConfig: (data: { ranges: string[]; interval_seconds: number }) => api.post('/scan/config', data),
+  saveConfig: (data: { ranges: string[] }) => api.post('/scan/config', data),
+}
+
+export const settingsApi = {
+  get: () => api.get<{ interval_seconds: number }>('/settings'),
+  save: (data: { interval_seconds: number }) => api.post<{ interval_seconds: number }>('/settings', data),
 }

frontend/src/components/canvas/CanvasContainer.tsx

@@ -27,7 +27,7 @@ export function CanvasContainer({ onConnect: onConnectProp, onEdgeDoubleClick, o
   const {
     nodes, edges,
     onNodesChange, onEdgesChange,
-    setSelectedNode,
+    setSelectedNode, snapshotHistory,
   } = useCanvasStore()
 
   const activeTheme = useThemeStore((s) => s.activeTheme)
@@ -59,6 +59,8 @@ export function CanvasContainer({ onConnect: onConnectProp, onEdgeDoubleClick, o
         onNodeDragStart={onNodeDragStart}
         nodeTypes={nodeTypes}
         edgeTypes={edgeTypes}
+        deleteKeyCode={['Backspace', 'Delete']}
+        onBeforeDelete={async () => { snapshotHistory(); return true }}
         snapToGrid
         snapGrid={[16, 16]}
         fitView

frontend/src/components/canvas/__tests__/CanvasContainer.test.tsx

@@ -143,4 +143,22 @@ describe('CanvasContainer', () => {
     render(<CanvasContainer />)
     expect(rfProps.snapGrid).toEqual([16, 16])
   })
+
+  // ── Delete key ────────────────────────────────────────────────────────────
+
+  it('sets deleteKeyCode to include both Backspace and Delete', () => {
+    render(<CanvasContainer />)
+    expect(rfProps.deleteKeyCode).toEqual(['Backspace', 'Delete'])
+  })
+
+  // ── onBeforeDelete snapshot ───────────────────────────────────────────────
+
+  it('onBeforeDelete calls snapshotHistory and returns true', async () => {
+    const snapshotHistory = vi.fn()
+    useCanvasStore.setState({ snapshotHistory } as unknown as Parameters<typeof useCanvasStore.setState>[0])
+    render(<CanvasContainer />)
+    const result = await (rfProps.onBeforeDelete as () => Promise<boolean>)()
+    expect(snapshotHistory).toHaveBeenCalledOnce()
+    expect(result).toBe(true)
+  })
 })

frontend/src/components/modals/ScanConfigModal.tsx

@@ -1,5 +1,5 @@
 import { useState, useEffect } from 'react'
-import { Plus, Trash2 } from 'lucide-react'
+import { Plus, Trash2, Settings } from 'lucide-react'
 import { Dialog, DialogContent, DialogHeader, DialogTitle, DialogFooter } from '@/components/ui/dialog'
 import { Button } from '@/components/ui/button'
 import { Input } from '@/components/ui/input'
@@ -15,16 +15,12 @@ interface ScanConfigModalProps {
 
 export function ScanConfigModal({ open, onClose, onScanNow }: ScanConfigModalProps) {
   const [ranges, setRanges] = useState<string[]>([''])
-  const [interval, setInterval] = useState(60)
   const [saving, setSaving] = useState(false)
 
   useEffect(() => {
     if (!open) return
     scanApi.getConfig()
-      .then((res) => {
+      .then((res) => setRanges(res.data.ranges.length > 0 ? res.data.ranges : ['']))
-        setRanges(res.data.ranges.length > 0 ? res.data.ranges : [''])
-        setInterval(res.data.interval_seconds)
-      })
       .catch(() => {/* use defaults */})
   }, [open])
 
@@ -33,7 +29,7 @@ export function ScanConfigModal({ open, onClose, onScanNow }: ScanConfigModalPro
     if (cleaned.length === 0) { toast.error('Add at least one IP range'); return }
     setSaving(true)
     try {
-      await scanApi.saveConfig({ ranges: cleaned, interval_seconds: interval })
+      await scanApi.saveConfig({ ranges: cleaned })
       toast.success('Scan config saved')
       onClose()
     } catch {
@@ -95,18 +91,10 @@ export function ScanConfigModal({ open, onClose, onScanNow }: ScanConfigModalPro
             </Button>
           </div>
 
-          {/* Status check interval */}
+          <p className="text-xs text-muted-foreground flex items-center gap-1.5">
-          <div className="space-y-1.5">
+            <Settings size={11} />
-            <Label className="text-sm text-muted-foreground">Status check interval (seconds)</Label>
+            Status check interval can be configured in the sidebar Settings.
-            <Input
+          </p>
-              type="number"
-              min={10}
-              max={3600}
-              value={interval}
-              onChange={(e) => setInterval(Number(e.target.value))}
-              className="font-mono text-sm bg-[#0d1117] border-border w-32"
-            />
-          </div>
         </div>
 
         <DialogFooter className="gap-2">

frontend/src/components/modals/__tests__/ScanConfigModal.test.tsx

@@ -13,11 +13,12 @@ vi.mock('sonner', () => ({ toast: { success: vi.fn(), error: vi.fn(), info: vi.f
 import { scanApi } from '@/api/client'
 import { toast } from 'sonner'
 
-const defaultConfig = { data: { ranges: ['192.168.1.0/24'], interval_seconds: 60 } }
+const defaultConfig = { data: { ranges: ['192.168.1.0/24'] } }
 
 describe('ScanConfigModal', () => {
   beforeEach(() => {
     vi.mocked(scanApi.getConfig).mockResolvedValue(defaultConfig as never)
+    vi.mocked(scanApi.saveConfig).mockReset()
     vi.mocked(scanApi.saveConfig).mockResolvedValue({} as never)
     vi.mocked(toast.success).mockReset()
     vi.mocked(toast.error).mockReset()
@@ -37,11 +38,14 @@ describe('ScanConfigModal', () => {
     expect(input).toBeDefined()
   })
 
-  it('loads interval from API on open', async () => {
+  it('saves only ranges (interval managed by settings endpoint)', async () => {
-    vi.mocked(scanApi.getConfig).mockResolvedValue({ data: { ranges: ['10.0.0.0/8'], interval_seconds: 120 } } as never)
+    vi.mocked(scanApi.getConfig).mockResolvedValue({ data: { ranges: ['10.0.0.0/8'] } } as never)
     render(<ScanConfigModal open onClose={vi.fn()} onScanNow={vi.fn()} />)
-    const input = await screen.findByDisplayValue('120')
+    await screen.findByDisplayValue('10.0.0.0/8')
-    expect(input).toBeDefined()
+    fireEvent.click(screen.getByRole('button', { name: 'Save' }))
+    await waitFor(() => {
+      expect(scanApi.saveConfig).toHaveBeenCalledWith({ ranges: ['10.0.0.0/8'] })
+    })
   })
 
   it('adds a new empty range on "Add range" click', async () => {
@@ -61,7 +65,7 @@ describe('ScanConfigModal', () => {
   })
 
   it('can remove a range when more than one exist', async () => {
-    vi.mocked(scanApi.getConfig).mockResolvedValue({ data: { ranges: ['192.168.1.0/24', '10.0.0.0/8'], interval_seconds: 60 } } as never)
+    vi.mocked(scanApi.getConfig).mockResolvedValue({ data: { ranges: ['192.168.1.0/24', '10.0.0.0/8'], } } as never)
     render(<ScanConfigModal open onClose={vi.fn()} onScanNow={vi.fn()} />)
     await screen.findByDisplayValue('192.168.1.0/24')
     // Both trash buttons should be enabled
@@ -70,7 +74,7 @@ describe('ScanConfigModal', () => {
   })
 
   it('shows error toast and does not save when all ranges are empty', async () => {
-    vi.mocked(scanApi.getConfig).mockResolvedValue({ data: { ranges: [''], interval_seconds: 60 } } as never)
+    vi.mocked(scanApi.getConfig).mockResolvedValue({ data: { ranges: [''], } } as never)
     render(<ScanConfigModal open onClose={vi.fn()} onScanNow={vi.fn()} />)
     await waitFor(() => expect(scanApi.getConfig).toHaveBeenCalled())
     fireEvent.click(screen.getByRole('button', { name: 'Save' }))
@@ -86,7 +90,7 @@ describe('ScanConfigModal', () => {
     await screen.findByDisplayValue('192.168.1.0/24')
     fireEvent.click(screen.getByRole('button', { name: 'Save' }))
     await waitFor(() => {
-      expect(scanApi.saveConfig).toHaveBeenCalledWith({ ranges: ['192.168.1.0/24'], interval_seconds: 60 })
+      expect(scanApi.saveConfig).toHaveBeenCalledWith({ ranges: ['192.168.1.0/24'] })
       expect(toast.success).toHaveBeenCalledWith('Scan config saved')
       expect(onClose).toHaveBeenCalledOnce()
     })

frontend/src/components/panels/DetailPanel.tsx

@@ -15,7 +15,7 @@ type SvcForm = { port: string; protocol: 'tcp' | 'udp'; service_name: string }
 const EMPTY_FORM: SvcForm = { port: '', protocol: 'tcp', service_name: '' }
 
 export function DetailPanel({ onEdit }: DetailPanelProps) {
-  const { nodes, selectedNodeId, setSelectedNode, deleteNode, updateNode } = useCanvasStore()
+  const { nodes, selectedNodeId, setSelectedNode, deleteNode, updateNode, snapshotHistory } = useCanvasStore()
   const node = nodes.find((n) => n.id === selectedNodeId)
 
   const [addingForNode, setAddingForNode] = useState<string | null>(null)
@@ -35,6 +35,7 @@ export function DetailPanel({ onEdit }: DetailPanelProps) {
 
   const handleDelete = () => {
     if (confirm(`Delete "${data.label}"?`)) {
+      snapshotHistory()
       deleteNode(node.id)
     }
   }

frontend/src/components/panels/Sidebar.tsx

@@ -1,15 +1,15 @@
 import { useState, useCallback, useEffect, useRef } from 'react'
-import { Plus, Save, ScanLine, ChevronLeft, ChevronRight, LayoutDashboard, Clock, EyeOff, Trash2, RefreshCw, Loader2, Square, Eye } from 'lucide-react'
+import { Plus, Save, ScanLine, ChevronLeft, ChevronRight, LayoutDashboard, Clock, EyeOff, Trash2, RefreshCw, Loader2, Square, Eye, Settings } from 'lucide-react'
 import { Logo } from '@/components/ui/Logo'
 import { Tooltip, TooltipContent, TooltipTrigger } from '@/components/ui/tooltip'
 import { useCanvasStore } from '@/stores/canvasStore'
-import { scanApi } from '@/api/client'
+import { scanApi, settingsApi } from '@/api/client'
 import { toast } from 'sonner'
 import { PendingDeviceModal, type PendingDevice } from '@/components/modals/PendingDeviceModal'
 
 const STANDALONE = import.meta.env.VITE_STANDALONE === 'true'
 
-type SidebarView = 'canvas' | 'pending' | 'hidden' | 'history'
+type SidebarView = 'canvas' | 'pending' | 'hidden' | 'history' | 'settings'
 
 const ALL_VIEWS = [
   { id: 'canvas' as SidebarView, icon: LayoutDashboard, label: 'Canvas' },
@@ -95,6 +95,7 @@ export function Sidebar({ onAddNode, onAddGroupRect, onScan, onSave, onNodeAppro
           {activeView === 'pending' && <PendingDevicesPanel onNodeApproved={onNodeApproved} />}
           {activeView === 'hidden' && <HiddenDevicesPanel />}
           {activeView === 'history' && <ScanHistoryPanel />}
+          {activeView === 'settings' && <SettingsPanel />}
         </div>
       )}
 
@@ -141,6 +142,15 @@ export function Sidebar({ onAddNode, onAddGroupRect, onScan, onSave, onNodeAppro
           badge={hasUnsavedChanges}
           accent
         />
+        {!STANDALONE && (
+          <SidebarItem
+            icon={Settings}
+            label="Settings"
+            collapsed={collapsed}
+            active={activeView === 'settings'}
+            onClick={() => setActiveView((v) => v === 'settings' ? 'canvas' : 'settings')}
+          />
+        )}
       </div>
     </aside>
   )
@@ -417,6 +427,61 @@ function ScanHistoryPanel() {
   )
 }
 
+function SettingsPanel() {
+  const [interval, setIntervalValue] = useState(60)
+  const [saving, setSaving] = useState(false)
+
+  useEffect(() => {
+    settingsApi.get()
+      .then((res) => setIntervalValue(res.data.interval_seconds))
+      .catch(() => {/* use default */})
+  }, [])
+
+  const handleSave = async () => {
+    setSaving(true)
+    try {
+      await settingsApi.save({ interval_seconds: interval })
+      toast.success('Settings saved')
+    } catch {
+      toast.error('Failed to save settings')
+    } finally {
+      setSaving(false)
+    }
+  }
+
+  return (
+    <div className="p-3 space-y-4">
+      <span className="text-xs font-medium text-muted-foreground uppercase tracking-wider">Settings</span>
+
+      <div className="space-y-1.5">
+        <label className="text-xs text-muted-foreground">Status check interval (s)</label>
+        <div className="flex items-center gap-2">
+          <input
+            type="number"
+            min={10}
+            max={3600}
+            value={interval}
+            onChange={(e) => setIntervalValue(Number(e.target.value))}
+            className="w-24 px-2 py-1 rounded-md text-xs font-mono bg-[#0d1117] border border-border text-foreground focus:outline-none focus:border-[#00d4ff]"
+          />
+          <span className="text-xs text-muted-foreground">seconds</span>
+        </div>
+        <p className="text-[10px] text-muted-foreground leading-tight">
+          How often node health is polled (ping, HTTP, SSH…)
+        </p>
+      </div>
+
+      <button
+        onClick={handleSave}
+        disabled={saving}
+        className="w-full py-1.5 rounded-md text-xs font-medium bg-[#00d4ff]/10 text-[#00d4ff] border border-[#00d4ff]/30 hover:bg-[#00d4ff]/20 transition-colors disabled:opacity-50"
+      >
+        {saving ? 'Saving…' : 'Save'}
+      </button>
+    </div>
+  )
+}
+
 const MAC_OUI: Record<string, { label: string; title: string }> = {
   '52:54:00': { label: 'QEMU', title: 'QEMU/KVM Virtual Machine' },
   'bc:24:11': { label: 'PVE',  title: 'Proxmox Virtual Machine or LXC' },

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

@@ -29,6 +29,7 @@ function setupStore(nodeData: Partial<NodeData> = {}) {
     setSelectedNode: vi.fn(),
     deleteNode: vi.fn(),
     updateNode: vi.fn(),
+    snapshotHistory: vi.fn(),
   } as unknown as ReturnType<typeof canvasStore.useCanvasStore>)
 }
 
@@ -40,6 +41,7 @@ describe('DetailPanel', () => {
       setSelectedNode: vi.fn(),
       deleteNode: vi.fn(),
       updateNode: vi.fn(),
+      snapshotHistory: vi.fn(),
     } as unknown as ReturnType<typeof canvasStore.useCanvasStore>)
   })
 
@@ -125,6 +127,7 @@ describe('DetailPanel', () => {
         setSelectedNode,
         deleteNode: vi.fn(),
         updateNode: vi.fn(),
+        snapshotHistory: vi.fn(),
       } as unknown as ReturnType<typeof canvasStore.useCanvasStore>)
       render(<DetailPanel onEdit={vi.fn()} />)
       fireEvent.click(screen.getByLabelText('Close panel'))
@@ -139,33 +142,39 @@ describe('DetailPanel', () => {
       expect(onEdit).toHaveBeenCalledWith('n1')
     })
 
-    it('calls deleteNode when delete confirmed', () => {
+    it('calls snapshotHistory then deleteNode when delete confirmed', () => {
       const deleteNode = vi.fn()
+      const snapshotHistory = vi.fn()
       vi.mocked(canvasStore.useCanvasStore).mockReturnValue({
         nodes: [makeNode({ label: 'My Server' })],
         selectedNodeId: 'n1',
         setSelectedNode: vi.fn(),
         deleteNode,
         updateNode: vi.fn(),
+        snapshotHistory,
       } as unknown as ReturnType<typeof canvasStore.useCanvasStore>)
       vi.spyOn(window, 'confirm').mockReturnValue(true)
       render(<DetailPanel onEdit={vi.fn()} />)
       fireEvent.click(screen.getByLabelText('Delete node'))
+      expect(snapshotHistory).toHaveBeenCalledOnce()
       expect(deleteNode).toHaveBeenCalledWith('n1')
     })
 
-    it('does not call deleteNode when delete is cancelled', () => {
+    it('does not call deleteNode or snapshotHistory when delete is cancelled', () => {
       const deleteNode = vi.fn()
+      const snapshotHistory = vi.fn()
       vi.mocked(canvasStore.useCanvasStore).mockReturnValue({
         nodes: [makeNode({})],
         selectedNodeId: 'n1',
         setSelectedNode: vi.fn(),
         deleteNode,
         updateNode: vi.fn(),
+        snapshotHistory,
       } as unknown as ReturnType<typeof canvasStore.useCanvasStore>)
       vi.spyOn(window, 'confirm').mockReturnValue(false)
       render(<DetailPanel onEdit={vi.fn()} />)
       fireEvent.click(screen.getByLabelText('Delete node'))
+      expect(snapshotHistory).not.toHaveBeenCalled()
       expect(deleteNode).not.toHaveBeenCalled()
     })
   })
@@ -186,6 +195,7 @@ describe('DetailPanel', () => {
         setSelectedNode: vi.fn(),
         deleteNode: vi.fn(),
         updateNode,
+        snapshotHistory: vi.fn(),
       } as unknown as ReturnType<typeof canvasStore.useCanvasStore>)
       render(<DetailPanel onEdit={vi.fn()} />)
       fireEvent.click(screen.getByText('Add'))
@@ -207,6 +217,7 @@ describe('DetailPanel', () => {
         setSelectedNode: vi.fn(),
         deleteNode: vi.fn(),
         updateNode,
+        snapshotHistory: vi.fn(),
       } as unknown as ReturnType<typeof canvasStore.useCanvasStore>)
       render(<DetailPanel onEdit={vi.fn()} />)
       fireEvent.click(screen.getByTitle('Remove service'))
@@ -221,6 +232,7 @@ describe('DetailPanel', () => {
         setSelectedNode: vi.fn(),
         deleteNode: vi.fn(),
         updateNode: vi.fn(),
+        snapshotHistory: vi.fn(),
       } as unknown as ReturnType<typeof canvasStore.useCanvasStore>)
       expect(() => render(<DetailPanel onEdit={vi.fn()} />)).not.toThrow()
     })
@@ -249,6 +261,7 @@ describe('DetailPanel', () => {
         setSelectedNode: vi.fn(),
         deleteNode: vi.fn(),
         updateNode,
+        snapshotHistory: vi.fn(),
       } as unknown as ReturnType<typeof canvasStore.useCanvasStore>)
 
       render(<DetailPanel onEdit={vi.fn()} />)
@@ -271,6 +284,7 @@ describe('DetailPanel', () => {
         setSelectedNode: vi.fn(),
         deleteNode: vi.fn(),
         updateNode,
+        snapshotHistory: vi.fn(),
       } as unknown as ReturnType<typeof canvasStore.useCanvasStore>)
 
       render(<DetailPanel onEdit={vi.fn()} />)

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

@@ -0,0 +1,104 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest'
+import { render, screen, fireEvent, waitFor } from '@testing-library/react'
+import { Sidebar } from '../Sidebar'
+import * as canvasStore from '@/stores/canvasStore'
+import { TooltipProvider } from '@/components/ui/tooltip'
+
+vi.mock('@/stores/canvasStore')
+vi.mock('sonner', () => ({ toast: { success: vi.fn(), error: vi.fn() } }))
+vi.mock('@/api/client', () => ({
+  scanApi: {
+    trigger: vi.fn(),
+    pending: vi.fn().mockResolvedValue({ data: [] }),
+    hidden: vi.fn().mockResolvedValue({ data: [] }),
+    runs: vi.fn().mockResolvedValue({ data: [] }),
+    getConfig: vi.fn().mockResolvedValue({ data: { ranges: [] } }),
+  },
+  settingsApi: {
+    get: vi.fn(),
+    save: vi.fn(),
+  },
+}))
+
+import { settingsApi } from '@/api/client'
+import { toast } from 'sonner'
+
+function renderSidebar() {
+  vi.mocked(canvasStore.useCanvasStore).mockReturnValue({
+    nodes: [],
+    hasUnsavedChanges: false,
+    hideIp: false,
+    toggleHideIp: vi.fn(),
+    addNode: vi.fn(),
+    scanEventTs: 0,
+  } as unknown as ReturnType<typeof canvasStore.useCanvasStore>)
+
+  return render(
+    <TooltipProvider>
+      <Sidebar
+        onAddNode={vi.fn()}
+        onAddGroupRect={vi.fn()}
+        onScan={vi.fn()}
+        onSave={vi.fn()}
+        onNodeApproved={vi.fn()}
+      />
+    </TooltipProvider>
+  )
+}
+
+describe('SettingsPanel', () => {
+  beforeEach(() => {
+    vi.mocked(settingsApi.get).mockResolvedValue({ data: { interval_seconds: 60 } } as never)
+    vi.mocked(settingsApi.save).mockResolvedValue({ data: { interval_seconds: 60 } } as never)
+    vi.mocked(toast.success).mockReset()
+    vi.mocked(toast.error).mockReset()
+  })
+
+  it('opens when Settings item is clicked', async () => {
+    renderSidebar()
+    fireEvent.click(screen.getByRole('button', { name: 'Settings' }))
+    await waitFor(() => {
+      expect(settingsApi.get).toHaveBeenCalledOnce()
+    })
+    expect(screen.getByText('Status check interval (s)')).toBeDefined()
+  })
+
+  it('displays interval loaded from API', async () => {
+    vi.mocked(settingsApi.get).mockResolvedValue({ data: { interval_seconds: 120 } } as never)
+    renderSidebar()
+    fireEvent.click(screen.getByRole('button', { name: 'Settings' }))
+    const input = await screen.findByDisplayValue('120')
+    expect(input).toBeDefined()
+  })
+
+  it('saves interval via settingsApi on Save click', async () => {
+    renderSidebar()
+    fireEvent.click(screen.getByRole('button', { name: 'Settings' }))
+    const input = await screen.findByDisplayValue('60')
+    fireEvent.change(input, { target: { value: '180' } })
+    fireEvent.click(screen.getByRole('button', { name: 'Save' }))
+    await waitFor(() => {
+      expect(settingsApi.save).toHaveBeenCalledWith({ interval_seconds: 180 })
+      expect(toast.success).toHaveBeenCalledWith('Settings saved')
+    })
+  })
+
+  it('shows error toast when save fails', async () => {
+    vi.mocked(settingsApi.save).mockRejectedValue(new Error('network'))
+    renderSidebar()
+    fireEvent.click(screen.getByRole('button', { name: 'Settings' }))
+    await screen.findByDisplayValue('60')
+    fireEvent.click(screen.getByRole('button', { name: 'Save' }))
+    await waitFor(() => {
+      expect(toast.error).toHaveBeenCalledWith('Failed to save settings')
+    })
+  })
+
+  it('closes panel when Settings is clicked again', async () => {
+    renderSidebar()
+    fireEvent.click(screen.getByRole('button', { name: 'Settings' }))
+    await screen.findByText('Status check interval (s)')
+    fireEvent.click(screen.getByRole('button', { name: 'Settings' }))
+    expect(screen.queryByText('Status check interval (s)')).toBeNull()
+  })
+})