1 files changed, 52 insertions, 2 deletions

diff --git a/internal/storage/db.go b/internal/storage/db.go
index 0e4d6f1..1aac754 100644
--- a/internal/storage/db.go
+++ b/internal/storage/db.go
@@ -359,6 +359,56 @@ func (s *DB) GetLatestExecution(taskID string) (*Execution, error) {
 	return scanExecution(row)
 }
 
+// DeleteTask removes a task and all its executions and subtasks (recursively).
+// Returns an error if the task does not exist.
+func (s *DB) DeleteTask(id string) error {
+	// Collect all task IDs to delete (the task + all descendant subtasks).
+	toDelete := []string{id}
+	// BFS over children.
+	queue := []string{id}
+	for len(queue) > 0 {
+		parentID := queue[0]
+		queue = queue[1:]
+		rows, err := s.db.Query(`SELECT id FROM tasks WHERE parent_task_id = ?`, parentID)
+		if err != nil {
+			return fmt.Errorf("listing subtasks of %q: %w", parentID, err)
+		}
+		for rows.Next() {
+			var childID string
+			if err := rows.Scan(&childID); err != nil {
+				rows.Close()
+				return err
+			}
+			toDelete = append(toDelete, childID)
+			queue = append(queue, childID)
+		}
+		rows.Close()
+		if err := rows.Err(); err != nil {
+			return err
+		}
+	}
+
+	// Delete executions for all collected tasks then the tasks themselves.
+	for _, tid := range toDelete {
+		if _, err := s.db.Exec(`DELETE FROM executions WHERE task_id = ?`, tid); err != nil {
+			return fmt.Errorf("deleting executions for task %q: %w", tid, err)
+		}
+	}
+	for _, tid := range toDelete {
+		result, err := s.db.Exec(`DELETE FROM tasks WHERE id = ?`, tid)
+		if err != nil {
+			return fmt.Errorf("deleting task %q: %w", tid, err)
+		}
+		if tid == id {
+			n, _ := result.RowsAffected()
+			if n == 0 {
+				return fmt.Errorf("task %q not found", id)
+			}
+		}
+	}
+	return nil
+}
+
 // UpdateTaskQuestion stores the pending question JSON on a task.
 // Pass empty string to clear the question after it has been answered.
 func (s *DB) UpdateTaskQuestion(taskID, questionJSON string) error {
@@ -371,10 +421,10 @@ func (s *DB) UpdateTaskQuestion(taskID, questionJSON string) error {
 func (s *DB) UpdateExecution(e *Execution) error {
 	_, err := s.db.Exec(`
 		UPDATE executions SET end_time = ?, exit_code = ?, status = ?, cost_usd = ?, error_msg = ?,
-		stdout_path = ?, stderr_path = ?, artifact_dir = ?
+		stdout_path = ?, stderr_path = ?, artifact_dir = ?, session_id = ?
 		WHERE id = ?`,
 		e.EndTime.UTC(), e.ExitCode, e.Status, e.CostUSD, e.ErrorMsg,
-		e.StdoutPath, e.StderrPath, e.ArtifactDir, e.ID,
+		e.StdoutPath, e.StderrPath, e.ArtifactDir, e.SessionID, e.ID,
 	)
 	return err
 }