fix(worker-client): stop swallowing mutating hub call failures

TryInvokeAsync catches every exception and returns null, which is fine
for read-only calls but hid real HubException reasons behind a generic
"offline" message for the 7 mutating call sites (RestoreDefaultAgents,
UpsertPrimeSchedule, AddDailyNote, CleanupFinishedWorktrees,
ResetAllWorktrees, ForceRemoveWorktree, BuildPlanningIntegrationBranch)
— the same bug class fixed for ApproveReview in e1807fd. Each of the 22
TryInvokeAsync call sites was audited; the 15 read-only ones are left
unchanged (empty/offline is the right display). For the 7 switched to
a direct hub invoke, every caller was checked and, where it had no
catch, one was added so the exception surfaces (StatusMessage,
ShowErrorAsync/CombinedWarning) instead of crashing.

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

@@ -174,6 +174,7 @@ public sealed partial class WorktreesOverviewModalViewModel : ViewModelBase
             StatusMessage = result is null ? Loc.T("vm.worktreesOverview.cleanupFailed") : Loc.T("vm.worktreesOverview.removed", result.Removed);
             await LoadAsync();
         }
+        catch (Exception ex) { StatusMessage = Loc.T("vm.worktreesOverview.cleanupFailedDetailed", ex.Message); }
         finally { IsBusy = false; }
     }
 
@@ -241,7 +242,16 @@ public sealed partial class WorktreesOverviewModalViewModel : ViewModelBase
         if (row.IsRunning) { StatusMessage = Loc.T("vm.worktreesOverview.cannotForceRunning"); return; }
         if (ConfirmAction is not null && !await ConfirmAction($"Force remove worktree for '{row.TaskTitle}'? This deletes the directory and branch.")) return;
 
-        var result = await _worker.ForceRemoveWorktreeAsync(row.TaskId);
+        ForceRemoveResultDto? result;
+        try
+        {
+            result = await _worker.ForceRemoveWorktreeAsync(row.TaskId);
+        }
+        catch (Exception ex)
+        {
+            StatusMessage = Loc.T("vm.worktreesOverview.forceRemoveFailedDetailed", ex.Message);
+            return;
+        }
         if (result is null || !result.Removed)
         {
             StatusMessage = result?.Reason ?? Loc.T("vm.worktreesOverview.forceRemoveFailed");