feat: System tray mode with background health monitoring

ARCHITECTURE.md

@@ -94,6 +94,8 @@ Key services:
   Recycle Bin, shortcut scan, disk SMART, uptime/RAM checks. Non-destructive.
 - `HealthScoreService` — aggregates disk health, RAM, uptime, and battery
   wear into a single 0–100 score with color-coded verdict and recommendations.
+- `TrayIconService` — system tray icon with background monitoring (60s),
+  tooltip updates, context menu, and Windows toast notifications.
 - `LogService` — Serilog wrapper with rolling file sink.
 - `FixedDriveService` — enumerate fixed NTFS/ReFS volumes.
 - `DeepCleanupService` — scan-first safe cleanup (vendor caches, gaming

CHANGELOG.md

@@ -20,6 +20,11 @@ adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
   with "Scan system". Closes #259.
 - **HealthScoreService** — aggregates SystemInfoService, DiskHealthService,
   and BatteryService into a weighted health score.
+- **System Tray mode** — minimize-to-tray on window close, background
+  health monitoring every 60 seconds, CPU/RAM/uptime tooltip on hover,
+  Windows toast notifications when RAM > 90%, uptime > 14 days, or disk
+  health degrades. Right-click context menu with Show / Exit. Uses
+  H.NotifyIcon.Wpf 2.2.1. Closes #262.
 - **IntGreaterThanZeroConverter** — value converter for conditional
   visibility when an integer is greater than zero.
 - **IDialogService** — abstraction for user confirmation dialogs, replacing

README.md

@@ -256,6 +256,9 @@ long-running operation, so you always know which tab is working.
   SMART, RAM usage, uptime, and battery wear. Color-coded ring (green /
   amber / red) with up to 3 actionable recommendations. Auto-computes on
   load and refreshes with "Scan system".
+- **System Tray** — minimize-to-tray on close, background health monitoring
+  (60s polling), CPU/RAM tooltip, Windows notifications when RAM > 90%,
+  uptime > 14 days, or disk health degrades. Context menu: Show / Exit.
 
 ### Updates (for SysManager itself)
 - Auto-check on startup against the GitHub Releases API, plus a manual

SysManager/SysManager.Tests/TrayIconServiceTests.cs

@@ -0,0 +1,135 @@
+// SysManager · TrayIconServiceTests
+// Author: laurentiu021 · https://github.com/laurentiu021/SystemManager
+// License: MIT
+
+using SysManager.Models;
+using SysManager.Services;
+
+namespace SysManager.Tests;
+
+/// <summary>
+/// Unit tests for <see cref="TrayIconService"/> — validates notification
+/// threshold logic and property defaults. Actual tray icon display is
+/// integration-level (requires UI thread + Windows shell).
+/// </summary>
+public class TrayIconServiceTests
+{
+    // ---------- construction & defaults ----------
+
+    [Fact]
+    public void Constructor_DoesNotThrow()
+    {
+        var svc = new TrayIconService(new SystemInfoService());
+        Assert.NotNull(svc);
+        svc.Dispose();
+    }
+
+    [Fact]
+    public void MinimizeToTray_DefaultTrue()
+    {
+        var svc = new TrayIconService(new SystemInfoService());
+        Assert.True(svc.MinimizeToTray);
+        svc.Dispose();
+    }
+
+    [Fact]
+    public void NotificationsEnabled_DefaultTrue()
+    {
+        var svc = new TrayIconService(new SystemInfoService());
+        Assert.True(svc.NotificationsEnabled);
+        svc.Dispose();
+    }
+
+    [Fact]
+    public void MinimizeToTray_CanBeDisabled()
+    {
+        var svc = new TrayIconService(new SystemInfoService());
+        svc.MinimizeToTray = false;
+        Assert.False(svc.MinimizeToTray);
+        svc.Dispose();
+    }
+
+    [Fact]
+    public void NotificationsEnabled_CanBeDisabled()
+    {
+        var svc = new TrayIconService(new SystemInfoService());
+        svc.NotificationsEnabled = false;
+        Assert.False(svc.NotificationsEnabled);
+        svc.Dispose();
+    }
+
+    [Fact]
+    public void Dispose_CalledTwice_DoesNotThrow()
+    {
+        var svc = new TrayIconService(new SystemInfoService());
+        svc.Dispose();
+        var ex = Record.Exception(() => svc.Dispose());
+        Assert.Null(ex);
+    }
+
+    // ---------- notification threshold logic ----------
+
+    [Fact]
+    public void CheckAndNotify_LowRam_DoesNotThrow()
+    {
+        // RAM at 50% — should NOT trigger notification
+        var svc = new TrayIconService(new SystemInfoService());
+        var snapshot = MakeSnapshot(ramUsedPct: 50, uptimeDays: 1);
+        var ex = Record.Exception(() => svc.CheckAndNotify(snapshot));
+        Assert.Null(ex);
+        svc.Dispose();
+    }
+
+    [Fact]
+    public void CheckAndNotify_HighRam_DoesNotThrow()
+    {
+        // RAM at 95% — should trigger notification (but no tray icon = no crash)
+        var svc = new TrayIconService(new SystemInfoService());
+        var snapshot = MakeSnapshot(ramUsedPct: 95, uptimeDays: 1);
+        var ex = Record.Exception(() => svc.CheckAndNotify(snapshot));
+        Assert.Null(ex);
+        svc.Dispose();
+    }
+
+    [Fact]
+    public void CheckAndNotify_HighUptime_DoesNotThrow()
+    {
+        var svc = new TrayIconService(new SystemInfoService());
+        var snapshot = MakeSnapshot(ramUsedPct: 50, uptimeDays: 20);
+        var ex = Record.Exception(() => svc.CheckAndNotify(snapshot));
+        Assert.Null(ex);
+        svc.Dispose();
+    }
+
+    [Fact]
+    public void CheckAndNotify_UnhealthyDisk_DoesNotThrow()
+    {
+        var svc = new TrayIconService(new SystemInfoService());
+        var snapshot = new SystemSnapshot(
+            new OsInfo("Windows 11", "10.0", "22631", TimeSpan.FromDays(1), "64-bit"),
+            new CpuInfo("Test CPU", 8, 16, 3600, 10),
+            new MemoryInfo(16, 8, 8, 50, new List<MemoryModule>()),
+            new List<DiskInfo>
+            {
+                new("TestDisk", "SSD", "NVMe", 500, "Warning", "OK", 45, 10)
+            },
+            DateTime.Now);
+        var ex = Record.Exception(() => svc.CheckAndNotify(snapshot));
+        Assert.Null(ex);
+        svc.Dispose();
+    }
+
+    // ---------- helpers ----------
+
+    private static SystemSnapshot MakeSnapshot(double ramUsedPct, int uptimeDays)
+    {
+        double totalGB = 16;
+        double usedGB = totalGB * ramUsedPct / 100;
+        return new SystemSnapshot(
+            new OsInfo("Windows 11", "10.0", "22631", TimeSpan.FromDays(uptimeDays), "64-bit"),
+            new CpuInfo("Test CPU", 8, 16, 3600, 10),
+            new MemoryInfo(totalGB, totalGB - usedGB, usedGB, ramUsedPct, new List<MemoryModule>()),
+            new List<DiskInfo>(),
+            DateTime.Now);
+    }
+}

SysManager/SysManager/App.xaml.cs

@@ -14,10 +14,14 @@ public partial class App : Application
 {
     private const string MutexName = "Global\\SysManager_SingleInstance_laurentiu021";
     private Mutex? _instanceMutex;
+    private TrayIconService? _trayService;
 
     // Guard against cascading error dialogs — show at most one at a time.
     private static int _errorDialogActive;
 
+    /// <summary>The shared tray icon service instance.</summary>
+    public TrayIconService? TrayService => _trayService;
+
     [DllImport("user32.dll")]
     private static extern bool SetForegroundWindow(IntPtr hWnd);
 
@@ -45,6 +49,13 @@ protected override void OnStartup(StartupEventArgs e)
         }
 
         LogService.Init();
+
+        // Don't shutdown when main window is hidden (tray mode)
+        ShutdownMode = ShutdownMode.OnExplicitShutdown;
+
+        // Initialize tray icon service
+        _trayService = new TrayIconService(new SystemInfoService());
+
         DispatcherUnhandledException += OnUi;
         AppDomain.CurrentDomain.UnhandledException += OnDomain;
         TaskScheduler.UnobservedTaskException += OnTask;
@@ -53,6 +64,7 @@ protected override void OnStartup(StartupEventArgs e)
 
     protected override void OnExit(ExitEventArgs e)
     {
+        _trayService?.Dispose();
         LogService.Shutdown();
         _instanceMutex?.ReleaseMutex();
         _instanceMutex?.Dispose();

SysManager/SysManager/MainWindow.xaml.cs

@@ -5,6 +5,7 @@
 using System.Windows;
 using System.Windows.Input;
 using System.Windows.Interop;
+using SysManager.Services;
 using SysManager.ViewModels;
 
 namespace SysManager;
@@ -29,6 +30,10 @@ protected override void OnSourceInitialized(EventArgs e)
         base.OnSourceInitialized(e);
         if (PresentationSource.FromVisual(this) is HwndSource source)
             source.AddHook(WndProc);
+
+        // Initialize tray icon after window handle is available
+        if (Application.Current is App app && app.TrayService != null)
+            app.TrayService.Initialize(this);
     }
 
     private IntPtr WndProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
@@ -63,6 +68,18 @@ private void NavChild_Click(object sender, MouseButtonEventArgs e)
             vm.SelectedNav = item;
     }
 
+    protected override void OnClosing(System.ComponentModel.CancelEventArgs e)
+    {
+        // Minimize to tray instead of closing (if enabled)
+        if (Application.Current is App app && app.TrayService is { MinimizeToTray: true })
+        {
+            e.Cancel = true;
+            TrayIconService.HideWindow(this);
+            return;
+        }
+        base.OnClosing(e);
+    }
+
     protected override void OnClosed(EventArgs e)
     {
         (DataContext as MainWindowViewModel)?.Dispose();