feat(claude-do): merge Task context menu: "Mark as → Idle" for cancelled tasks

ClaudeDo-Task: ad39dbb38d314e96803decc4e194e180

src/ClaudeDo.Localization/locales/de.json

@@ -209,6 +209,7 @@
     "ctxMarkAs": "Markieren als",
     "ctxMarkDone": "Erledigt",
     "ctxMarkCancelled": "Abgebrochen",
+    "ctxMarkIdle": "Offen",
     "ctxOpenConPtySession": "Interaktive Sitzung öffnen",
     "ctxOpenWorktree": "Worktree öffnen",
     "ctxOpenPlanningSession": "Planungssitzung öffnen",

src/ClaudeDo.Localization/locales/en.json

@@ -209,6 +209,7 @@
     "ctxMarkAs": "Mark as",
     "ctxMarkDone": "Done",
     "ctxMarkCancelled": "Cancelled",
+    "ctxMarkIdle": "Idle",
     "ctxOpenConPtySession": "Open interactive session",
     "ctxOpenWorktree": "Open worktree",
     "ctxOpenPlanningSession": "Open planning Session",

src/ClaudeDo.Ui/Views/Islands/TaskRowView.axaml.cs

@@ -70,6 +70,7 @@ public partial class TaskRowView : UserControl
         var markAs = new MenuItem { Header = Loc.T("tasks.ctxMarkAs"), DataContext = row };
         markAs.Items.Add(MakeItem("tasks.ctxMarkDone", OnSetStatusClick, tag: "Done", reason: row.MarkAsDisabledReason));
         markAs.Items.Add(MakeItem("tasks.ctxMarkCancelled", OnSetStatusClick, tag: "Cancelled", reason: row.MarkAsDisabledReason));
+        markAs.Items.Add(MakeItem("tasks.ctxMarkIdle", OnSetStatusClick, row.Status == TaskStatus.Cancelled, tag: "Idle", reason: row.MarkAsDisabledReason));
         markAs.Items.Add(new Separator());
         markAs.Items.Add(MakeItem("tasks.ctxMarkManual", OnToggleManualClick, !row.IsManual));
         markAs.Items.Add(MakeItem("tasks.ctxMarkClaudeTask", OnToggleManualClick, row.IsManual));

src/ClaudeDo.Worker/Hub/WorkerHub.cs

@@ -677,10 +677,14 @@ public sealed class WorkerHub : Microsoft.AspNetCore.SignalR.Hub
             throw new HubException("Cannot change the status of a running task. Cancel it first.");
 
         // Queueing goes through the gated transition so draft subtasks can't be queued;
+        // Idle goes through ResetToIdleAsync so StartedAt/FinishedAt/Result are cleared;
         // other statuses keep the unconditional "set status freely" affordance.
-        var result = parsed == TaskStatus.Queued
-            ? await _state.EnqueueAsync(taskId, Context.ConnectionAborted)
-            : await _state.ForceSetStatusAsync(taskId, parsed, Context.ConnectionAborted);
+        var result = parsed switch
+        {
+            TaskStatus.Queued => await _state.EnqueueAsync(taskId, Context.ConnectionAborted),
+            TaskStatus.Idle => await _state.ResetToIdleAsync(taskId, Context.ConnectionAborted),
+            _ => await _state.ForceSetStatusAsync(taskId, parsed, Context.ConnectionAborted),
+        };
         if (!result.Ok) throw new HubException(result.Reason ?? "set status failed");
         return new SetTaskStatusResultDto(
             result.BaseDirty is { } w ? new BaseDirtyWarningDto(w.ModifiedCount, w.UntrackedCount) : null);