fix: resolve critical bugs and improve reliability across worker, data, UI

- Fix worker using wrong DB by defaulting to CurrentUser service account
  and expanding ~ to absolute paths at install time
- Fix DbContext disposed before fire-and-forget by passing taskId instead
  of TaskEntity into RunInSlotAsync, which creates its own context
- Fix ActiveTaskDto property casing mismatch between hub and client
- Move WAL mode PRAGMA before migrations to prevent concurrent lock issues
- Replace FirstAsync with FirstOrDefaultAsync + null guards in tag operations
- Add delete confirmation flow for lists
- Log fire-and-forget exceptions instead of swallowing them
- Broadcast RunCreated event from WorkerHub.RunNow
- Add IDisposable to MainWindowViewModel for event handler cleanup
- Preserve subtask CreatedAt on updates instead of overwriting
- Replace bare catch blocks with Debug.WriteLine logging

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/ClaudeDo.Worker/Hub/WorkerHub.cs

@@ -5,6 +5,8 @@ using Microsoft.AspNetCore.SignalR;
 
 namespace ClaudeDo.Worker.Hub;
 
+public record ActiveTaskDto(string Slot, string TaskId, DateTime StartedAt);
+
 public sealed class WorkerHub : Microsoft.AspNetCore.SignalR.Hub
 {
     private static readonly string Version =
@@ -12,19 +14,21 @@ public sealed class WorkerHub : Microsoft.AspNetCore.SignalR.Hub
 
     private readonly QueueService _queue;
     private readonly AgentFileService _agentService;
+    private readonly HubBroadcaster _broadcaster;
 
-    public WorkerHub(QueueService queue, AgentFileService agentService)
+    public WorkerHub(QueueService queue, AgentFileService agentService, HubBroadcaster broadcaster)
     {
         _queue = queue;
         _agentService = agentService;
+        _broadcaster = broadcaster;
     }
 
     public string Ping() => $"pong v{Version}";
 
-    public IReadOnlyList<object> GetActive()
+    public IReadOnlyList<ActiveTaskDto> GetActive()
     {
         return _queue.GetActive()
-            .Select(a => (object)new { slot = a.slot, taskId = a.taskId, startedAt = a.startedAt })
+            .Select(a => new ActiveTaskDto(a.slot, a.taskId, a.startedAt))
             .ToList();
     }
 
@@ -33,6 +37,7 @@ public sealed class WorkerHub : Microsoft.AspNetCore.SignalR.Hub
         try
         {
             await _queue.RunNow(taskId);
+            await _broadcaster.RunCreated(taskId, 1, false);
         }
         catch (InvalidOperationException)
         {