chore(claude-do): merge Unit-Branch Teil 1: Branch-Naming + Basis-Branch pro Liste

ClaudeDo-Task: e202e601-64c0-4ecb-8dc9-2fb0da01a84a

src/ClaudeDo.Ui/ViewModels/Modals/ListSettingsModalViewModel.cs

@@ -59,6 +59,8 @@ public sealed partial class ListSettingsModalViewModel : ViewModelBase
     // harvests new work, longer handoff chain) when this AND the global switch in Settings →
     // Execution are both on. Off by default — the global switch alone must never change a list's behaviour.
     [ObservableProperty] private bool _powerUseAllowed;
+    // Basis neuer Worktrees und Default-Merge-Ziel; leer = ausgecheckter Branch.
+    [ObservableProperty] private string _baseBranch = "";
     // Dropdown hidden entirely when no ticket-system base URL is configured (Settings → Files tab).
     // Icon key into the UI icon library (IconKeyConverter -> "Icon.<key>" StreamGeometry).
     [ObservableProperty] private string _icon = DefaultIcon;
@@ -308,6 +310,7 @@ public sealed partial class ListSettingsModalViewModel : ViewModelBase
             cfg = Agent.LastLoadedListConfig;
             VerifyCommand = cfg?.VerifyCommand ?? "";
             PowerUseAllowed = cfg?.PowerUseAllowed ?? false;
+            BaseBranch = cfg?.BaseBranch ?? "";
         }
         catch (Exception ex)
         {
@@ -411,7 +414,9 @@ public sealed partial class ListSettingsModalViewModel : ViewModelBase
         await Agent.SaveAsync(
             string.IsNullOrWhiteSpace(VerifyCommand) ? null : VerifyCommand,
             ticketProjectId,
-            PowerUseAllowed);
+            PowerUseAllowed,
+            // Always explicit too: "" clears the stored base branch.
+            BaseBranch.Trim());
 
         Saved = true;
         CloseAction?.Invoke();