Initial commit: EngineeringSync v1.0.0

Vollständige Implementierung des EngineeringSync-Middleware-Tools:
- Windows Service (Kestrel :5050) mit FileSystemWatcher + SignalR
- WPF Tray-App mit PendingChanges- und Projektverwaltungs-Fenster
- Setup-Wizard (8-Schritte-Installer)
- SQLite/EF Core Datenschicht (WAL-Modus)
- SHA-256-basiertes Debouncing (2s Fenster)
- Backup-System mit konfigurierbarer Aufbewahrung

Bugfixes & Verbesserungen:
- BUG-1: AppDbContext OnConfiguring invertierte Bedingung behoben
- BUG-2: Event-Handler-Leak in TrayApp (Fenster-Singleton-Pattern)
- BUG-3: ProjectConfigChanged SignalR-Signal in allen CRUD-Endpoints
- BUG-5: Rename-Sync löscht alte Datei im Simulations-Ordner
- BUG-6: Doppeltes Dispose von SignalR verhindert
- BUG-7: Registry-Deinstallation nur EngineeringSync-Eintrag entfernt
- S1: Path-Traversal-Schutz via SafeCombine() im SyncManager
- E1: FSW Buffer 64KB + automatischer Re-Scan bei Overflow
- E2: Retry-Logik (3x) für gesperrte Dateien mit exponentiellem Backoff
- E4: Channel.Writer.TryComplete() beim Shutdown
- C2: HubMethodNames-Konstanten statt Magic Strings
- E3: Pagination in Changes-API (page/pageSize Query-Parameter)
- A1: Fire-and-Forget mit try/catch + Logging

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

EngineeringSync.TrayApp/Services/SignalRService.cs

@@ -0,0 +1,57 @@
+using EngineeringSync.Domain.Constants;
+using Microsoft.AspNetCore.SignalR.Client;
+
+namespace EngineeringSync.TrayApp.Services;
+
+public class SignalRService : IAsyncDisposable
+{
+    private HubConnection? _connection;
+
+    public event Action<Guid, string, int>? ChangeNotificationReceived;
+    public event Action? ProjectConfigChanged;
+
+    public async Task ConnectAsync(CancellationToken ct = default)
+    {
+        _connection = new HubConnectionBuilder()
+            .WithUrl("http://localhost:5050/notifications")
+            .WithAutomaticReconnect([TimeSpan.Zero, TimeSpan.FromSeconds(2),
+                TimeSpan.FromSeconds(5), TimeSpan.FromSeconds(10)])
+            .Build();
+
+        // Register handlers on initial connection
+        RegisterHandlers();
+
+        // Re-register handlers when reconnected after disconnection
+        _connection.Reconnected += async (connectionId) =>
+        {
+            RegisterHandlers();
+            await Task.CompletedTask;
+        };
+
+        await _connection.StartAsync(ct);
+    }
+
+    private void RegisterHandlers()
+    {
+        if (_connection is null)
+            return;
+
+        // Remove existing handlers to prevent duplicates
+        _connection.Remove(HubMethodNames.ReceiveChangeNotification);
+        _connection.Remove(HubMethodNames.ProjectConfigChanged);
+
+        // Register handlers
+        _connection.On<Guid, string, int>(HubMethodNames.ReceiveChangeNotification,
+            (projectId, projectName, count) =>
+                ChangeNotificationReceived?.Invoke(projectId, projectName, count));
+
+        _connection.On(HubMethodNames.ProjectConfigChanged,
+            () => ProjectConfigChanged?.Invoke());
+    }
+
+    public async ValueTask DisposeAsync()
+    {
+        if (_connection is not null)
+            await _connection.DisposeAsync();
+    }
+}