refactor(app): implement year filtering for accounts and enhance dashboard PDF generation

src/Duempelkas.App/Pages/Dashboard.razor

@@ -4,6 +4,7 @@
 @inject ISettingsService SettingsService
 @inject IPdfStatementService PdfStatementService
 @inject IFileSaveService FileSaveService
+@inject IEntryService EntryService
 @inject NavigationManager NavigationManager
 
 <div class="container-fluid">
@@ -34,6 +35,10 @@
         <button class="btn-nav btn-dark" @onclick="HandleDashboardExportAsync">
             <i class="bi bi-file-earmark-pdf"></i> PDF
         </button>
+        |
+        <button class="btn btn-nav btn-primary" @onclick="OpenYearFilterDialog">
+            <i class="bi bi-funnel"></i> Ansicht<br>@GetFilterLabel()
+        </button>
     </div>
 
     @if (accounts != null && accounts.Any())
@@ -107,3 +112,29 @@
                    OnCancel="CancelRestoreConfirm" />
 }
 
+@if (showYearFilterDialog)
+{
+    <div class="dialog-backdrop" @onclick="CloseYearFilterDialog">
+        <div class="dialog-content" @onclick:stopPropagation="true">
+            <h5>Filter auswählen</h5>
+            <p class="text-muted mb-3">Wähle ein Jahr oder alle Buchungen.</p>
+            <div class="filter-options-grid">
+                <button class="btn @(selectedYear.HasValue ? "btn-outline-secondary" : "btn-primary")" @onclick="() => SelectFilterYear(null)">
+                    Alle Buchungen
+                </button>
+                @foreach (var year in availableYears)
+                {
+                    <button class="btn @(selectedYear == year ? "btn-primary" : "btn-outline-secondary")" @onclick="() => SelectFilterYear(year)">
+                        @year
+                    </button>
+                }
+            </div>
+            <div class="d-flex justify-content-end mt-3">
+                <button class="btn btn-outline-secondary" @onclick="CloseYearFilterDialog">
+                    <i class="bi bi-x-lg"></i> Schließen
+                </button>
+            </div>
+        </div>
+    </div>
+}
+