feat(desktop): add monitor scheduler, Playwright CDP layer, and account health

Move monitor-task scheduling authority onto the client with a durable
file-backed queue that survives restart, drops stale cross-day tasks,
enforces per-platform serialism, and adapts global concurrency from
Electron process metrics. Publish tasks keep their existing FIFO.

Add a hidden Playwright CDP manager that attaches to Electron Chromium
on account session partitions, lets adapters opt into `executionMode:
"playwright"`, and leaves the existing hidden WebContentsView path in
place for current adapters.

Introduce an account-health subsystem with silent probes, projected
health/auth states, and IPC invalidation events so the renderer can
show accurate auth/probe status and verification timestamps.

Server-side, derive and forward title/business_date/scheduler_group_key/
question_text metadata on desktop task events so the local scheduler
can defer same-question fan-out before leasing.

server/internal/tenant/app/desktop_task_service.go

@@ -725,17 +725,22 @@ func (s *DesktopTaskService) publishTaskEvent(ctx context.Context, task *reposit
 		return
 	}
 
+	title, businessDate, schedulerGroupKey, questionText := deriveDesktopTaskEventMetadataFromPayload(task.Kind, task.Payload)
 	err := publishDesktopTaskEvent(ctx, s.messaging, DesktopTaskEvent{
-		Type:            eventType,
-		TaskID:          task.DesktopID.String(),
-		JobID:           task.JobID.String(),
-		WorkspaceID:     task.WorkspaceID,
-		TargetAccountID: task.TargetAccountID.String(),
-		TargetClientID:  task.TargetClientID.String(),
-		Platform:        task.Platform,
-		Status:          task.Status,
-		Kind:            task.Kind,
-		UpdatedAt:       task.UpdatedAt,
+		Type:              eventType,
+		TaskID:            task.DesktopID.String(),
+		JobID:             task.JobID.String(),
+		WorkspaceID:       task.WorkspaceID,
+		TargetAccountID:   task.TargetAccountID.String(),
+		TargetClientID:    task.TargetClientID.String(),
+		Platform:          task.Platform,
+		Title:             title,
+		BusinessDate:      businessDate,
+		SchedulerGroupKey: schedulerGroupKey,
+		QuestionText:      questionText,
+		Status:            task.Status,
+		Kind:              task.Kind,
+		UpdatedAt:         task.UpdatedAt,
 	})
 	if err != nil {
 		s.logWarn("desktop task event publish failed", err, zap.String("task_id", task.DesktopID.String()), zap.String("event_type", eventType))