refactor: delete unreachable members and redundant package refs

Eight public members had no caller anywhere in src: GitService.GetFileDiffAsync,
SubtaskRepository.DeleteByTaskIdAsync, TaskRepository.GetByListAsync (a
backwards-compat alias for GetByListIdAsync) and .GetByCreatorAsync,
WorktreeRepository.GetByStatesAsync, TaskMonitorViewModel.SetPendingQuestion
(a duplicate of the live-event lambda), PrimeClaudeTabViewModel.ApplyFiredEvent,
and StreamLineFormatter.FormatFile. TaskAttachmentRepository.DeleteAllForTaskAsync
was reachable only from its own test; the ON DELETE CASCADE on task_attachments
already covers it. Tests for the deleted members go with them.

Dropped two package refs the platform already provides: EntityFrameworkCore.Design
in Worker (the design-time factory and the migrations live in Data, which has its
own ref) and System.IO.FileSystem.AccessControl in Installer.Tests (net8.0-windows
ships the ACL APIs in the shared framework).

src/ClaudeDo.Ui/Helpers/StreamLineFormatter.cs

@@ -312,18 +312,6 @@ public class StreamLineFormatter
         return s.Length <= max ? s : s[..max] + "…";
     }
 
-    public string FormatFile(string filePath)
-    {
-        var sb = new StringBuilder();
-        foreach (var line in File.ReadLines(filePath))
-        {
-            var formatted = FormatLine(line);
-            if (formatted is not null)
-                sb.Append(formatted);
-        }
-        return Trim(sb.ToString());
-    }
-
     public static string Trim(string text)
     {
         if (text.Length <= MaxLength) return text;

src/ClaudeDo.Ui/ViewModels/Islands/TaskMonitorViewModel.cs

@@ -140,13 +140,6 @@ public sealed partial class TaskMonitorViewModel : ViewModelBase, IDisposable
         _worker.TaskQuestionResolvedEvent += _onTaskQuestionResolved;
     }
 
-    // Surface a pending question (used by live event + re-attach hydration).
-    public void SetPendingQuestion(string questionId, string question)
-    {
-        PendingQuestionId = questionId;
-        PendingQuestion = question;
-    }
-
     private void ClearPendingQuestion()
     {
         PendingQuestionId = null;

src/ClaudeDo.Ui/ViewModels/Modals/Settings/PrimeClaudeTabViewModel.cs

@@ -100,10 +100,4 @@ public sealed partial class PrimeClaudeTabViewModel : ViewModelBase
         Rows.Remove(row);
     }
 
-    public void ApplyFiredEvent(PrimeFiredEvent evt)
-    {
-        var row = Rows.FirstOrDefault(r => r.Id == evt.ScheduleId);
-        if (row is null) return;
-        if (evt.Success) row.LastRunAt = evt.FiredAt;
-    }
 }