feat(ui): Bilder aus der Zwischenablage ins interaktive Terminal einfuegen

Ctrl+V mit einem Bild in der Zwischenablage schreibt es als temporaeres
PNG unter ~/.claudeDo/tmp/ und fuegt den Pfad in den Composer ein, genau
wie ein Datei-Drop -- Claude liest die Datei selbst. Text-Paste laeuft
unveraendert ueber den bestehenden bracketed-paste-Pfad.

Avalonia 12.0.4 liest Clipboard-Bitmaps bereits selbst (IClipboard.
TryGetDataAsync + AsyncDataTransferExtensions.TryGetBitmapAsync), kein
Win32-P/Invoke noetig. Alte Tmp-Dateien (>24h) werden beim App-Start
aufgeraeumt (ClaudeDo.App/Program.cs), keine eigene Aufraeum-Infrastruktur.

src/ClaudeDo.Ui/Views/InteractiveTerminalView.axaml.cs

@@ -1,10 +1,12 @@
 using System;
 using System.Collections.Generic;
+using System.IO;
 using System.Linq;
 using Avalonia.Controls;
 using Avalonia.Input;
 using Avalonia.Interactivity;
 using Avalonia.Platform.Storage;
+using ClaudeDo.Ui.Services;
 using ClaudeDo.Ui.ViewModels;
 
 namespace ClaudeDo.Ui.Views;
@@ -43,13 +45,54 @@ public partial class InteractiveTerminalView : UserControl
         if (DataContext is not InteractiveTerminalViewModel vm) return;
 
         e.Handled = true;
-        _ = PasteAndReportAsync(vm);
+        _ = PasteAndReportAsync(this, vm);
     }
 
-    private static async System.Threading.Tasks.Task PasteAndReportAsync(InteractiveTerminalViewModel vm)
+    // A clipboard image (e.g. a screenshot) can't be typed into the child process, so it's written
+    // to a temp PNG and its path is inserted the same way a dropped file is — Claude reads the file
+    // itself. Plain-text clipboard content keeps going through the existing bracketed-paste flow.
+    // Once a bitmap is confirmed present, any failure (dir/file write, send) is a real paste
+    // failure — never silently fall back to a text paste of the same clipboard.
+    private static async System.Threading.Tasks.Task PasteAndReportAsync(InteractiveTerminalView view, InteractiveTerminalViewModel vm)
     {
-        if (!await vm.PasteAsync())
+        Avalonia.Media.Imaging.Bitmap? bitmap = null;
+        try
+        {
+            bitmap = await TryGetClipboardBitmapAsync(TopLevel.GetTopLevel(view));
+            if (bitmap is null)
+            {
+                if (!await vm.PasteAsync()) vm.ReportSendFailed();
+                return;
+            }
+
+            var path = ClipboardImageTempStore.NewPngPath(DateTime.UtcNow);
+            Directory.CreateDirectory(ClipboardImageTempStore.Directory);
+            bitmap.Save(path);
+            if (!await vm.SendTextAsync(FormatDroppedPaths(new[] { path })))
+                vm.ReportSendFailed();
+        }
+        catch (Exception)
+        {
             vm.ReportSendFailed();
+        }
+        finally
+        {
+            bitmap?.Dispose();
+        }
+    }
+
+    private static async System.Threading.Tasks.Task<Avalonia.Media.Imaging.Bitmap?> TryGetClipboardBitmapAsync(TopLevel? topLevel)
+    {
+        if (topLevel?.Clipboard is not { } clipboard) return null;
+        try
+        {
+            using var data = await clipboard.TryGetDataAsync();
+            return data is null ? null : await Avalonia.Input.AsyncDataTransferExtensions.TryGetBitmapAsync(data);
+        }
+        catch (Exception)
+        {
+            return null;
+        }
     }
 
     private static bool IsFilesDrop(DragEventArgs e) => e.DataTransfer?.Contains(DataFormat.File) == true;