@

Integrate analytics feature stack with Watchdog/License host integration

Merges the full copytrading-analytics stack (UI fixes, insider feed, fingerprint
snapshot foundation, strategy-drift alarm, edge-freshness, smart-money co-movement
detection + graph clustering, copy-portfolio) with the WinFormsHost Watchdog
heartbeat + LicenseLabrador license gate. No file overlap between the two lines.
@

docs/BETRIEB-Watchdog-Lizenz.md

@@ -0,0 +1,82 @@
+# Betrieb: Watchdog-Überwachung & LicenseLabrador-Lizenzierung
+
+Beide Integrationen sitzen im `Predictalytics.WinFormsHost` (dem Produktiv-Host) und
+binden zwei eigenständige Schwester-Projekte an:
+
+| Projekt | Pfad | Rolle |
+|---|---|---|
+| Watchdog | `J:\Softwareprojekte\WatchDog` | PHP/MySQL-Server auf `watchdog.mhdf.de`, empfängt Heartbeats |
+| LicenseLabrador | `J:\Softwareprojekte\LicenseLabrador` | PHP-Lizenzserver auf `license.mhdf.de` + C#-SDK |
+
+---
+
+## 1. Watchdog (Dead-Man's-Switch)
+
+`Services/WatchdogHeartbeatService.cs` sendet alle *n* Sekunden einen
+`POST /api/heartbeat` an den Watchdog. Bleiben die Heartbeats aus — weil die App
+abgestürzt ist oder die ganze Maschine weg ist — schlägt der Watchdog Alarm.
+Beim regulären Schließen geht ein `POST /api/event` mit `kind=stopped_graceful`
+raus, damit ein geplantes Beenden nicht als Crash alarmiert wird.
+
+> **Nicht auf `kind=stopping` ändern.** Der Watchdog akzeptiert den Wert im
+> Router, aber `event_log.kind` ist ein ENUM ohne `stopping`. Der Server setzt
+> dann zwar noch den Zustand auf `stopped`, scheitert aber am Insert und liefert
+> HTTP 500 — das Event fehlt in der Historie. Verifiziert am 2026-07-30.
+
+**Wichtig:** Ein Ausfall des Watchdogs darf Predictalytics nie beeinträchtigen.
+Alle Aufrufe sind best effort; der erste Fehlschlag wird als Warnung geloggt,
+Folgefehler nur noch auf Debug-Level (keine Log-Flut).
+
+### Konfiguration (PropertyGrid im Host, Kategorie „Watchdog")
+
+| Feld | Default | Bedeutung |
+|---|---|---|
+| `Enabled` | `true` | Heartbeats an/aus |
+| `Server URL` | `https://watchdog.mhdf.de` | Basis-URL |
+| `API Key` | *(leer)* | `X-Watchdog-Key` — Shared Key **oder** Agent-Token. Ohne Key passiert nichts. |
+| `Source` | `Predictalytics` | Monitor-Name im Dashboard (Auto-Registrierung beim ersten Beat) |
+| `Instance` | `default` | falls mehrere Instanzen laufen |
+| `Interval (Sekunden)` | `60` | Sende-Takt; Alarm nach ca. `Intervall × 1,5 + 30 s` |
+
+Der Key landet in der `settings.json` neben der Exe (nicht im Git).
+
+### PolyTrader-Maschine mit überwachen
+
+Der Heartbeat aus Predictalytics deckt nur *diesen* Prozess ab. Damit auch die
+Maschine überwacht wird, auf der PolyTrader läuft, gehört dort zusätzlich der
+OS-Agent hin: `WatchDog\agents\windows\watchdog-agent.ps1` als Scheduled Task
+(inkl. Shutdown-Hook), bzw. `agents/linux/watchdog-agent.sh` per systemd-Timer.
+
+---
+
+## 2. LicenseLabrador (Kopierschutz)
+
+`Services/LicenseGuard.cs` prüft beim Start, ob eine nutzbare Lizenz vorliegt
+(`Program.Main` bricht sonst ab, bevor die MainForm überhaupt entsteht).
+Ohne gültige Lizenz erscheint `Services/LicenseDialog.cs` zur Key-Eingabe.
+
+Produkt-Slug, Endpoint und der Ed25519-Public-Key sind **bewusst einkompiliert**
+und nicht konfigurierbar — ein einstellbarer Endpoint würde erlauben, die App auf
+einen gefälschten Lizenzserver zu zeigen.
+
+- **Produkt-Slug:** `predictalytics`
+- **Offline-Gnadenfrist:** 168 h (7 Tage) — danach ist Serverkontakt nötig
+- **Revalidierung zur Laufzeit:** alle 12 h; bei Widerruf/Ablauf beendet sich die App
+- **Härtung:** `VerifyChecksum` (HMAC über State + Key + Hardware-ID) gegen Memory-Patches;
+  Nonce-Reflexion und Signaturprüfung übernimmt das SDK
+
+### Status
+
+Produkt `predictalytics` und Lizenzschlüssel sind angelegt; die Aktivierung wurde
+am 2026-07-30 gegen den Produktivserver verifiziert (`Valid`, gültig bis
+2040-12-31, Checksum-Prüfung bestanden). Der einkompilierte Public Key passt zum
+`signing.pub` des Servers — sonst käme `TamperSuspected` statt `Valid`.
+
+Die Aktivierung ist an die Hardware-ID der jeweiligen Maschine gebunden. Auf
+einem neuen Rechner erscheint einmalig der Dialog; der Cache liegt danach unter
+`%AppData%\predictalytics\license`.
+
+### Deaktivierung bei PC-Wechsel
+
+`LicenseClient.DeactivateAsync()` gibt die Aktivierung wieder frei. Aktuell nicht
+in der UI verdrahtet — bei Bedarf als Menüpunkt ergänzen.

src/Predictalytics.WinFormsHost/AppSettings.cs

@@ -27,6 +27,42 @@ public class AppSettings
     [Editor("System.ComponentModel.Design.MultilineStringEditor, System.Design, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a", typeof(System.Drawing.Design.UITypeEditor))]
     public string EgressChannelsText { get => _egressChannelsText; set => _egressChannelsText = value ?? ""; }
 
+    [Category("Watchdog")]
+    [DisplayName("Enabled")]
+    [Description("Sendet periodische Heartbeats an den externen Watchdog-Server (Dead-Man's-Switch). Benötigt einen API Key.")]
+    [DefaultValue(true)]
+    public bool WatchdogEnabled { get; set; } = true;
+
+    [Category("Watchdog")]
+    [DisplayName("Server URL")]
+    [Description("Basis-URL des Watchdog-Servers.")]
+    [DefaultValue("https://watchdog.mhdf.de")]
+    public string WatchdogUrl { get; set; } = "https://watchdog.mhdf.de";
+
+    [Category("Watchdog")]
+    [DisplayName("API Key")]
+    [Description("Shared Key oder Agent-Token des Watchdog-Servers (X-Watchdog-Key). Ohne Key werden keine Heartbeats gesendet.")]
+    [PasswordPropertyText(true)]
+    public string WatchdogApiKey { get; set; } = "";
+
+    [Category("Watchdog")]
+    [DisplayName("Source")]
+    [Description("Eindeutiger Monitor-Name dieses Dienstes im Watchdog-Dashboard.")]
+    [DefaultValue("Predictalytics")]
+    public string WatchdogSource { get; set; } = "Predictalytics";
+
+    [Category("Watchdog")]
+    [DisplayName("Instance")]
+    [Description("Instanz-Kennung, falls mehrere Predictalytics-Instanzen laufen.")]
+    [DefaultValue("default")]
+    public string WatchdogInstance { get; set; } = "default";
+
+    [Category("Watchdog")]
+    [DisplayName("Interval (Sekunden)")]
+    [Description("Sende-Takt der Heartbeats. Der Watchdog alarmiert, wenn ~1,5× dieses Intervall + 30 s ohne Heartbeat vergehen.")]
+    [DefaultValue(60)]
+    public int WatchdogIntervalSeconds { get; set; } = 60;
+
     private string _dbServer = "localhost";
     private string _dbName = "";
     private string _dbUser = "";

src/Predictalytics.WinFormsHost/MainForm.cs

@@ -11,6 +11,7 @@ public partial class MainForm : Form
     private bool _workerRunning;
     private bool _webServerRunning;
     private AppSettings _settings = null!;
+    private WatchdogHeartbeatService? _watchdog;
 
     /// <summary>Exposes the terminal RichTextBox for the Serilog sink.</summary>
     public RichTextBox Terminal => rtb_terminal;
@@ -40,6 +41,7 @@ public partial class MainForm : Form
                 _webServer.DbConnectionDebug = _settings.DbConnectionDebug;
                 _webServer.EgressChannelsText = _settings.EgressChannelsText;
             }
+            RestartWatchdog();
         };
 
         _webServer = new EmbeddedWebServer();
@@ -69,6 +71,39 @@ public partial class MainForm : Form
         var dbSizeTimer = new System.Windows.Forms.Timer { Interval = 6 * 60 * 60 * 1000 };
         dbSizeTimer.Tick += async (s, e) => await UpdateDbSizeAsync();
         dbSizeTimer.Start();
+
+        RestartWatchdog();
+    }
+
+    /// <summary>
+    /// (Re-)creates the Watchdog heartbeat sender from the current settings.
+    /// Called at startup and whenever settings change.
+    /// </summary>
+    private void RestartWatchdog()
+    {
+        _watchdog?.Dispose();
+        _watchdog = null;
+
+        if (!_settings.WatchdogEnabled) return;
+
+        if (string.IsNullOrWhiteSpace(_settings.WatchdogApiKey) || string.IsNullOrWhiteSpace(_settings.WatchdogUrl))
+        {
+            Log.Information("🐕 Watchdog ist aktiviert, aber URL/API Key fehlen — bitte in den Settings eintragen.");
+            return;
+        }
+
+        _watchdog = new WatchdogHeartbeatService(
+            _settings.WatchdogUrl,
+            _settings.WatchdogApiKey,
+            _settings.WatchdogSource,
+            _settings.WatchdogInstance,
+            _settings.WatchdogIntervalSeconds,
+            metadataProvider: () => new
+            {
+                workersRunning = _workerRunning,
+                webserverRunning = _webServerRunning
+            });
+        _watchdog.Start();
     }
 
     private async void Btn_serverstart_Click(object? sender, EventArgs e)
@@ -142,6 +177,9 @@ public partial class MainForm : Form
 
     protected override void OnFormClosing(FormClosingEventArgs e)
     {
+        _watchdog?.NotifyStopping();
+        _watchdog?.Dispose();
+        _watchdog = null;
         _workerCts?.Cancel();
         _webServer?.StopWebServerAsync().GetAwaiter().GetResult();
         base.OnFormClosing(e);

src/Predictalytics.WinFormsHost/Predictalytics.WinFormsHost.csproj

@@ -31,6 +31,8 @@
     <ProjectReference Include="..\Predictalytics.Api\Predictalytics.Api.csproj" />
     <ProjectReference Include="..\Predictalytics.Worker\Predictalytics.Worker.csproj" />
     <ProjectReference Include="..\Predictalytics.Infrastructure\Predictalytics.Infrastructure.csproj" />
+    <!-- Externes Schwester-Repo: J:\Softwareprojekte\LicenseLabrador muss neben dem Predictalytics-Checkout liegen. -->
+    <ProjectReference Include="..\..\..\..\LicenseLabrador\client-dotnet\LicenseLabrador.Client\LicenseLabrador.Client.csproj" />
   </ItemGroup>
 
   <Target Name="CleanupLocalization" AfterTargets="Build">

src/Predictalytics.WinFormsHost/Program.cs

@@ -1,4 +1,5 @@
 using Predictalytics.Infrastructure.Logging;
+using Predictalytics.WinFormsHost.Services;
 using Serilog;
 using Serilog.Events;
 
@@ -11,6 +12,13 @@ internal static class Program
     {
         ApplicationConfiguration.Initialize();
 
+        // ─── License gate: no usable license, no app ───
+        var licenseClient = LicenseGuard.EnsureLicensed();
+        if (licenseClient == null)
+        {
+            return;
+        }
+
         var mainForm = new MainForm();
         var rtbWriteAction = TerminalHelper.CreateWriteAction(mainForm.Terminal, mainForm);
 
@@ -145,6 +153,10 @@ internal static class Program
         Log.Warning("══════════════════════════════════════════════════════");
 
         mainForm.Initialize();
+
+        // While running: re-check the license every 12 h (revocation/expiry/offline grace).
+        using var licenseTimer = LicenseGuard.StartPeriodicRevalidation(licenseClient);
+
         System.Windows.Forms.Application.Run(mainForm);
 
         Log.Information("Application shutting down.");

src/Predictalytics.WinFormsHost/Services/LicenseDialog.cs

@@ -0,0 +1,118 @@
+using LicenseLabrador.Client;
+
+namespace Predictalytics.WinFormsHost.Services;
+
+/// <summary>
+/// Modal dialog shown at startup when no usable license is present.
+/// Lets the user enter/activate a license key; closes with OK only after a
+/// successful, checksum-verified validation.
+/// </summary>
+public sealed class LicenseDialog : Form
+{
+    private readonly LicenseClient _client;
+    private readonly Label _lblStatus;
+    private readonly TextBox _txtKey;
+    private readonly Button _btnActivate;
+    private readonly Button _btnExit;
+
+    public LicenseResult? Result { get; private set; }
+
+    public LicenseDialog(LicenseClient client, LicenseResult? lastResult)
+    {
+        _client = client;
+
+        Text = "Predictalytics — Lizenzaktivierung";
+        FormBorderStyle = FormBorderStyle.FixedDialog;
+        MaximizeBox = false;
+        MinimizeBox = false;
+        StartPosition = FormStartPosition.CenterScreen;
+        ClientSize = new Size(460, 190);
+
+        var lblInfo = new Label
+        {
+            Text = "Diese Installation benötigt eine gültige Lizenz.\nBitte Lizenzschlüssel eingeben (Format: XXXXX-XXXXX-XXXXX-XXXXX-XXXXX):",
+            Location = new Point(12, 12),
+            Size = new Size(436, 34)
+        };
+
+        _txtKey = new TextBox
+        {
+            Location = new Point(12, 52),
+            Size = new Size(436, 26),
+            Font = new Font("Consolas", 11f),
+            CharacterCasing = CharacterCasing.Upper
+        };
+
+        _lblStatus = new Label
+        {
+            Location = new Point(12, 84),
+            Size = new Size(436, 50),
+            ForeColor = Color.Firebrick,
+            Text = FormatInitialStatus(lastResult)
+        };
+
+        _btnActivate = new Button
+        {
+            Text = "Aktivieren",
+            Location = new Point(252, 146),
+            Size = new Size(96, 30)
+        };
+        _btnActivate.Click += async (_, _) => await ActivateAsync();
+
+        _btnExit = new Button
+        {
+            Text = "Beenden",
+            Location = new Point(354, 146),
+            Size = new Size(94, 30),
+            DialogResult = DialogResult.Cancel
+        };
+
+        AcceptButton = _btnActivate;
+        CancelButton = _btnExit;
+        Controls.AddRange(new Control[] { lblInfo, _txtKey, _lblStatus, _btnActivate, _btnExit });
+    }
+
+    private static string FormatInitialStatus(LicenseResult? lastResult)
+    {
+        if (lastResult == null || lastResult.State == LicenseState.NoLicense) return "";
+        return $"Letzte Prüfung: {lastResult.State} — {lastResult.Message}";
+    }
+
+    private async Task ActivateAsync()
+    {
+        var key = _txtKey.Text.Trim();
+        if (string.IsNullOrWhiteSpace(key))
+        {
+            _lblStatus.Text = "Bitte einen Lizenzschlüssel eingeben.";
+            return;
+        }
+
+        _btnActivate.Enabled = false;
+        _lblStatus.ForeColor = Color.DimGray;
+        _lblStatus.Text = "Prüfe Lizenz am Server...";
+
+        try
+        {
+            var result = await _client.ValidateAsync(key);
+            if (result.IsUsable && _client.VerifyChecksum(result))
+            {
+                Result = result;
+                DialogResult = DialogResult.OK;
+                Close();
+                return;
+            }
+
+            _lblStatus.ForeColor = Color.Firebrick;
+            _lblStatus.Text = $"Lizenz nicht nutzbar ({result.State}):\n{result.Message}";
+        }
+        catch (Exception ex)
+        {
+            _lblStatus.ForeColor = Color.Firebrick;
+            _lblStatus.Text = $"Fehler bei der Prüfung: {ex.Message}";
+        }
+        finally
+        {
+            _btnActivate.Enabled = true;
+        }
+    }
+}

src/Predictalytics.WinFormsHost/Services/LicenseGuard.cs

@@ -0,0 +1,98 @@
+using LicenseLabrador.Client;
+using Serilog;
+
+namespace Predictalytics.WinFormsHost.Services;
+
+/// <summary>
+/// Startup license gate backed by the LicenseLabrador server.
+/// Endpoint, product slug and the Ed25519 public key are deliberately compiled in
+/// (not user configuration): a configurable endpoint/key would let anyone point the
+/// app at a fake license server.
+/// </summary>
+public static class LicenseGuard
+{
+    private const string ProductSlug = "predictalytics";
+    private const string PublicKeyBase64 = "L7YR1wMKk8+lNefatzL+DMvAtHFVkZWYXAxXGrro+/U=";
+    private const string BasicAuthUser = "Labrador";
+    private const string BasicAuthPassword = "Labrador02763!";
+    private static readonly string[] Endpoints = { "http://license.mhdf.de/public/api/v1" };
+
+    /// <summary>Re-check interval while the app is running (12 h).</summary>
+    public const int RevalidationIntervalMs = 12 * 60 * 60 * 1000;
+
+    public static LicenseClient CreateClient()
+    {
+        var config = new LicenseConfig
+        {
+            ProductSlug = ProductSlug,
+            PublicKeyBase64 = PublicKeyBase64,
+            Endpoints = Endpoints,
+            HttpBasicAuthUser = BasicAuthUser,
+            HttpBasicAuthPassword = BasicAuthPassword,
+            OfflineGraceHoursFallback = 168 // 7 Tage offline nutzbar, danach Serverkontakt nötig
+        };
+        return new LicenseClient(config);
+    }
+
+    /// <summary>
+    /// Blocks until a usable license is present. Tries the cached key first; otherwise
+    /// (or when the cached key is no longer usable) shows the license dialog.
+    /// Returns null if the user gave up — the app must exit then.
+    /// </summary>
+    public static LicenseClient? EnsureLicensed()
+    {
+        var client = CreateClient();
+
+        var result = client.RevalidateAsync().GetAwaiter().GetResult();
+        if (result.IsUsable && client.VerifyChecksum(result))
+        {
+            return client;
+        }
+
+        using var dialog = new LicenseDialog(client, result);
+        if (dialog.ShowDialog() != DialogResult.OK)
+        {
+            return null;
+        }
+        return client;
+    }
+
+    /// <summary>
+    /// Starts the periodic in-app revalidation. Detects revocation/expiry while the app
+    /// keeps running; on a definitively unusable license the app is shut down.
+    /// </summary>
+    public static System.Windows.Forms.Timer StartPeriodicRevalidation(LicenseClient client)
+    {
+        var timer = new System.Windows.Forms.Timer { Interval = RevalidationIntervalMs };
+        timer.Tick += async (_, _) =>
+        {
+            try
+            {
+                var result = await client.RevalidateAsync();
+                if (result.IsUsable && client.VerifyChecksum(result))
+                {
+                    if (result.State == LicenseState.ValidOffline)
+                    {
+                        Log.Warning("Lizenzserver nicht erreichbar — Offline-Gnadenfrist läuft bis {GraceUntil}.", result.GraceUntil);
+                    }
+                    return;
+                }
+
+                timer.Stop();
+                Log.Fatal("Lizenzprüfung fehlgeschlagen ({State}): {Message} — Anwendung wird beendet.", result.State, result.Message);
+                MessageBox.Show(
+                    $"Die Lizenz ist nicht mehr gültig ({result.State}):\n{result.Message}\n\nPredictalytics wird beendet.",
+                    "Lizenzfehler", MessageBoxButtons.OK, MessageBoxIcon.Stop);
+                System.Windows.Forms.Application.Exit();
+            }
+            catch (Exception ex)
+            {
+                // Transient errors (network etc.) are handled by the SDK's offline grace —
+                // never kill the app from an unexpected exception here.
+                Log.Warning(ex, "Periodische Lizenz-Revalidierung fehlgeschlagen (wird erneut versucht).");
+            }
+        };
+        timer.Start();
+        return timer;
+    }
+}

src/Predictalytics.WinFormsHost/Services/WatchdogHeartbeatService.cs

@@ -0,0 +1,141 @@
+using System.Text;
+using System.Text.Json;
+using Serilog;
+
+namespace Predictalytics.WinFormsHost.Services;
+
+/// <summary>
+/// Sends periodic dead-man's-switch heartbeats to the external Watchdog server
+/// (POST /api/heartbeat) so an outage of this app — or the whole machine — raises
+/// an alarm. A Watchdog outage must never impact the app: every call is best effort.
+/// </summary>
+public sealed class WatchdogHeartbeatService : IDisposable
+{
+    private readonly HttpClient _http = new() { Timeout = TimeSpan.FromSeconds(10) };
+    private readonly string _baseUrl;
+    private readonly string _apiKey;
+    private readonly string _source;
+    private readonly string _instance;
+    private readonly int _intervalSeconds;
+    private readonly Func<object?>? _metadataProvider;
+    private readonly DateTime _startedUtc = DateTime.UtcNow;
+
+    private System.Threading.Timer? _timer;
+    private bool _lastSendFailed;
+
+    public WatchdogHeartbeatService(
+        string baseUrl,
+        string apiKey,
+        string source,
+        string instance,
+        int intervalSeconds,
+        Func<object?>? metadataProvider = null)
+    {
+        _baseUrl = baseUrl.TrimEnd('/');
+        _apiKey = apiKey;
+        _source = source;
+        _instance = string.IsNullOrWhiteSpace(instance) ? "default" : instance;
+        _intervalSeconds = Math.Max(15, intervalSeconds);
+        _metadataProvider = metadataProvider;
+    }
+
+    public void Start()
+    {
+        _timer?.Dispose();
+        _timer = new System.Threading.Timer(
+            async _ => await SendHeartbeatAsync("ok"),
+            null, TimeSpan.Zero, TimeSpan.FromSeconds(_intervalSeconds));
+        Log.Information("🐕 Watchdog heartbeat started → {Url} (source={Source}, every {Interval}s)",
+            _baseUrl, _source, _intervalSeconds);
+    }
+
+    /// <summary>
+    /// Reports a planned shutdown so it is not alarmed as a crash.
+    /// Must be "stopped_graceful": the server's event_log.kind ENUM has no "stopping"
+    /// value, and that variant fails the insert with HTTP 500 after the state update.
+    /// </summary>
+    public void NotifyStopping()
+    {
+        try
+        {
+            var payload = new
+            {
+                source = _source,
+                instance = _instance,
+                kind = "stopped_graceful",
+                severity = "info",
+                message = "Predictalytics wird planmäßig beendet."
+            };
+            // Synchronous with a short cap: the form is closing and must not hang.
+            PostAsync("/api/event", payload).Wait(TimeSpan.FromSeconds(4));
+        }
+        catch
+        {
+            // Best effort only.
+        }
+    }
+
+    private async Task SendHeartbeatAsync(string status)
+    {
+        try
+        {
+            var payload = new
+            {
+                source = _source,
+                instance = _instance,
+                type = "heartbeat",
+                status,
+                message = (string?)null,
+                metrics = new
+                {
+                    uptimeSec = (long)(DateTime.UtcNow - _startedUtc).TotalSeconds,
+                    app = _metadataProvider?.Invoke()
+                },
+                group = "C# Applications",
+                interval = _intervalSeconds
+            };
+
+            await PostAsync("/api/heartbeat", payload);
+
+            if (_lastSendFailed)
+            {
+                _lastSendFailed = false;
+                Log.Information("🐕 Watchdog heartbeat wieder erfolgreich zugestellt.");
+            }
+        }
+        catch (Exception ex)
+        {
+            // Log the first failure as warning, subsequent ones quietly (no log flood).
+            if (!_lastSendFailed)
+            {
+                _lastSendFailed = true;
+                Log.Warning("🐕 Watchdog heartbeat fehlgeschlagen (weitere Fehler werden unterdrückt): {Error}", ex.Message);
+            }
+            else
+            {
+                Log.Debug(ex, "Watchdog heartbeat failed");
+            }
+        }
+    }
+
+    private async Task PostAsync(string path, object payload)
+    {
+        using var request = new HttpRequestMessage(HttpMethod.Post, _baseUrl + path);
+        request.Headers.Add("X-Watchdog-Key", _apiKey);
+        request.Content = new StringContent(JsonSerializer.Serialize(payload), Encoding.UTF8, "application/json");
+
+        using var response = await _http.SendAsync(request);
+        if (!response.IsSuccessStatusCode)
+        {
+            var body = await response.Content.ReadAsStringAsync();
+            throw new HttpRequestException($"Watchdog API HTTP {(int)response.StatusCode}: {body}");
+        }
+    }
+
+    public void Dispose()
+    {
+        _timer?.Dispose();
+        _timer = null;
+        _http.Dispose();
+    }
+}