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/Settings/WorktreesSettingsTabViewModel.cs

@@ -46,6 +46,7 @@ public sealed partial class WorktreesSettingsTabViewModel : ViewModelBase
             var r = await _worker.CleanupFinishedWorktreesAsync();
             StatusMessage = r is null ? Loc.T("vm.worktreesTab.workerOffline") : Loc.T("vm.worktreesTab.removed", r.Removed);
         }
+        catch (Exception ex) { StatusMessage = Loc.T("vm.worktreesTab.cleanupFailed", ex.Message); }
         finally { IsBusy = false; }
     }
 
@@ -63,6 +64,7 @@ public sealed partial class WorktreesSettingsTabViewModel : ViewModelBase
             else if (r.Blocked) StatusMessage = Loc.T("vm.worktreesTab.blocked", r.RunningTasks);
             else StatusMessage = Loc.T("vm.worktreesTab.removedFrom", r.Removed, r.TasksAffected);
         }
+        catch (Exception ex) { StatusMessage = Loc.T("vm.worktreesTab.resetFailed", ex.Message); }
         finally { IsBusy = false; }
     }
 }