fix(ui): report failed paste/drop in the interactive terminal

PasteAsync silently swallowed every exception and returned void, so a
package update renaming Iciclecreek's private write seam would break
Ctrl+V/drop with zero user-visible signal. PasteAsync/SendTextAsync now
return bool (mirroring SendLineAsync), and the view checks the result,
routing a failure through InteractiveTerminalViewModel.ErrorReported ->
ConPtyPaneViewModel.ErrorReported -> the existing footer error strip.

src/ClaudeDo.Localization/locales/de.json

@@ -384,6 +384,7 @@
     "conptyStarting": "Sitzung wird gestartet…",
     "conptyExited": "Sitzung beendet (Code {0}).",
     "usageWarningNotDelivered": "Die Listen-Handler-Sitzung konnte nicht vor dem Usage-Limit gewarnt werden.",
+    "terminalSendFailed": "Konnte nicht an die Terminal-Sitzung gesendet werden.",
     "mergeHelperTitle": "Merge-Helfer",
     "mergeHelperHandoffTitleSuffix": " (Übergabe)",
     "mergeHelperTaskTitle": "Listen-Handler: {0}",

src/ClaudeDo.Localization/locales/en.json

@@ -384,6 +384,7 @@
     "conptyStarting": "Starting session…",
     "conptyExited": "Session ended (code {0}).",
     "usageWarningNotDelivered": "Couldn't warn the list-handler session about the usage limit.",
+    "terminalSendFailed": "Couldn't send that to the terminal session.",
     "mergeHelperTitle": "Merge Helper",
     "mergeHelperHandoffTitleSuffix": " (Handoff)",
     "mergeHelperTaskTitle": "List handler: {0}",

src/ClaudeDo.Ui/Services/PtyTerminalSession.cs

@@ -162,15 +162,19 @@ public sealed class PtyTerminalSession : IDisposable
     /// writing the clipboard text raw, because that is what honours bracketed-paste mode — without
     /// it a multi-line paste is read line by line and submits on the first newline.
     /// </summary>
-    public async Task PasteAsync()
+    public async Task<bool> PasteAsync()
     {
-        if (_control is not { } control || !IsRunning) return;
+        if (_control is not { } control || !IsRunning) return false;
         try
         {
-            if (s_terminalViewField?.GetValue(control) is TerminalView view)
-                await view.PasteAsync();
+            if (s_terminalViewField?.GetValue(control) is not TerminalView view) return false;
+            await view.PasteAsync();
+            return true;
+        }
+        catch (Exception)
+        {
+            return false;
         }
-        catch (Exception) { /* best-effort, same as SendLineAsync */ }
     }
 
     // Long enough that the two writes can't be read as one chunk by the child's stdin reader.

src/ClaudeDo.Ui/ViewModels/InteractiveTerminalViewModel.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Threading.Tasks;
 using CommunityToolkit.Mvvm.ComponentModel;
+using ClaudeDo.Ui.Localization;
 using ClaudeDo.Ui.Services;
 using Iciclecreek.Terminal;
 
@@ -111,6 +112,15 @@ public sealed partial class InteractiveTerminalViewModel : ViewModelBase, IDispo
         }
     }
 
+    /// <summary>Raised when a user-initiated paste or drop couldn't reach the session (write seam
+    /// gone, no running process) — mirrors the island ViewModels' ErrorReported, forwarded by
+    /// <see cref="ClaudeDo.Ui.ViewModels.MissionControl.ConPtyPaneViewModel"/> into the footer error strip.</summary>
+    public event Action<string>? ErrorReported;
+
+    /// <summary>Called by the view after a failed <see cref="PasteAsync"/>/<see cref="SendTextAsync"/>
+    /// so the failure surfaces through <see cref="ErrorReported"/> instead of vanishing silently.</summary>
+    public void ReportSendFailed() => ErrorReported?.Invoke(Loc.T("missionControl.terminalSendFailed"));
+
     /// <summary>Raised when the process died non-zero *after* clearing <see cref="StartupGraceWindow"/> —
     /// i.e. a session that ran, then broke. That used to be a silent dead tile with no signal at all;
     /// the worker turns it into a usage-limit auto-restart for list-handler sessions
@@ -156,8 +166,9 @@ public sealed partial class InteractiveTerminalViewModel : ViewModelBase, IDispo
     public Task<bool> SendTextAsync(string text) => _session.SendTextAsync(text);
 
     /// <summary>Pastes the clipboard into the session (Ctrl+V) — see
-    /// <see cref="PtyTerminalSession.PasteAsync"/>.</summary>
-    public Task PasteAsync() => _session.PasteAsync();
+    /// <see cref="PtyTerminalSession.PasteAsync"/>. False when there is no running process to
+    /// paste into (or the write seam is gone).</summary>
+    public Task<bool> PasteAsync() => _session.PasteAsync();
 
     public void Kill() => _session.Kill();
 

src/ClaudeDo.Ui/ViewModels/MissionControl/ConPtyPaneViewModel.cs

@@ -89,14 +89,18 @@ public sealed partial class ConPtyPaneViewModel : ViewModelBase, IDisposable
     {
         terminal.PropertyChanged += OnTerminalPropertyChanged;
         terminal.ExitedAfterStartup += OnTerminalExitedAfterStartup;
+        terminal.ErrorReported += OnTerminalErrorReported;
     }
 
     private void Unsubscribe(InteractiveTerminalViewModel terminal)
     {
         terminal.PropertyChanged -= OnTerminalPropertyChanged;
         terminal.ExitedAfterStartup -= OnTerminalExitedAfterStartup;
+        terminal.ErrorReported -= OnTerminalErrorReported;
     }
 
+    private void OnTerminalErrorReported(string message) => ErrorReported?.Invoke(message);
+
     private void OnTerminalExitedAfterStartup(int exitCode)
     {
         if (TaskId is { } id) SessionDiedAfterStartup?.Invoke(id, exitCode);

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

@@ -43,7 +43,13 @@ public partial class InteractiveTerminalView : UserControl
         if (DataContext is not InteractiveTerminalViewModel vm) return;
 
         e.Handled = true;
-        _ = vm.PasteAsync();
+        _ = PasteAndReportAsync(vm);
+    }
+
+    private static async System.Threading.Tasks.Task PasteAndReportAsync(InteractiveTerminalViewModel vm)
+    {
+        if (!await vm.PasteAsync())
+            vm.ReportSendFailed();
     }
 
     private static bool IsFilesDrop(DragEventArgs e) => e.DataTransfer?.Contains(DataFormat.File) == true;
@@ -62,7 +68,13 @@ public partial class InteractiveTerminalView : UserControl
         e.Handled = true;
 
         var text = FormatDroppedPaths(e.DataTransfer!.TryGetFiles()?.Select(i => i.TryGetLocalPath()));
-        if (text.Length > 0) _ = vm.SendTextAsync(text);
+        if (text.Length > 0) _ = SendTextAndReportAsync(vm, text);
+    }
+
+    private static async System.Threading.Tasks.Task SendTextAndReportAsync(InteractiveTerminalViewModel vm, string text)
+    {
+        if (!await vm.SendTextAsync(text))
+            vm.ReportSendFailed();
     }
 
     /// <summary>Joins dropped file paths into one insertable chunk: quoted when they contain a

tests/ClaudeDo.Ui.Tests/Services/PtyTerminalSessionTests.cs

@@ -35,4 +35,14 @@ public class PtyTerminalSessionTests
 
         Assert.Equal(0, gate.CurrentCount); // acquired
     }
+
+    // Fix: PasteAsync used to be void and swallow every failure. Not-started is the cheap case to
+    // cover without a real TerminalControl/ConPTY spawn.
+    [Fact]
+    public async Task PasteAsync_ReturnsFalse_WhenNotStarted()
+    {
+        using var session = new PtyTerminalSession();
+
+        Assert.False(await session.PasteAsync());
+    }
 }

tests/ClaudeDo.Ui.Tests/ViewModels/MissionControl/ConPtyPaneViewModelTests.cs

@@ -219,6 +219,35 @@ public class ConPtyPaneViewModelTests
         Assert.True(raised);
     }
 
+    // ── Terminal.ErrorReported forwarding (fix: a failed paste/drop had no path to the footer
+    //    error strip) ────────────────────────────────────────────────────────────────────────────
+
+    [Fact]
+    public void TerminalErrorReported_Forwards_ToPaneErrorReported()
+    {
+        using var pane = NewTaskPane(NeverCompletes);
+        string? error = null;
+        pane.ErrorReported += msg => error = msg;
+
+        pane.Terminal.ReportSendFailed();
+
+        Assert.NotNull(error);
+    }
+
+    [Fact]
+    public void TerminalErrorReported_StillWiredAfterRetry()
+    {
+        using var pane = NewTaskPane(() => Failing());
+        pane.Start();
+        pane.RetryCommand.Execute(null);
+        string? error = null;
+        pane.ErrorReported += msg => error = msg;
+
+        pane.Terminal.ReportSendFailed();
+
+        Assert.NotNull(error);
+    }
+
     private static void SetRunning(ConPtyPaneViewModel pane) => pane.Terminal.IsRunning = true;
 
     // Drives the terminal past its startup grace window, then kills it: IsRunning stamps the launch

tests/ClaudeDo.Ui.Tests/ViewModels/MissionControl/InteractiveTerminalViewModelTests.cs

@@ -124,4 +124,35 @@ public class InteractiveTerminalViewModelTests
         terminal.IsRunning = true; // records LaunchedAt via the first clock call
         return terminal;
     }
+
+    // ── Paste/drop failure reporting (fix: PasteAsync used to swallow every exception and return
+    //    void, so a failed Ctrl+V or file drop gave the user no signal at all) ────────────────────
+
+    [Fact]
+    public async Task PasteAsync_ReturnsFalse_WhenSessionNotRunning()
+    {
+        using var terminal = new InteractiveTerminalViewModel();
+
+        Assert.False(await terminal.PasteAsync());
+    }
+
+    [Fact]
+    public async Task SendTextAsync_ReturnsFalse_WhenSessionNotRunning()
+    {
+        using var terminal = new InteractiveTerminalViewModel();
+
+        Assert.False(await terminal.SendTextAsync("dropped/path"));
+    }
+
+    [Fact]
+    public void ReportSendFailed_RaisesErrorReported()
+    {
+        using var terminal = new InteractiveTerminalViewModel();
+        string? error = null;
+        terminal.ErrorReported += msg => error = msg;
+
+        terminal.ReportSendFailed();
+
+        Assert.NotNull(error);
+    }
 }