fix: clear question_json when restarting a task via ResetTaskForRetry

A BLOCKED task that fails on resume would keep its stale question_json
after being restarted. The frontend then showed "waiting for your input"
with the old prompt even though the task was running fresh.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

2 files changed, 36 insertions, 1 deletions

diff --git a/internal/storage/db.go b/internal/storage/db.go
index 5ba0786..aaf1e09 100644
--- a/internal/storage/db.go
+++ b/internal/storage/db.go
@@ -237,7 +237,7 @@ func (s *DB) ResetTaskForRetry(id string) (*task.Task, error) {
 	configJSON, _ := json.Marshal(t.Agent)
 
 	now := time.Now().UTC()
-	if _, err := tx.Exec(`UPDATE tasks SET state = ?, config_json = ?, updated_at = ? WHERE id = ?`,
+	if _, err := tx.Exec(`UPDATE tasks SET state = ?, config_json = ?, question_json = NULL, updated_at = ? WHERE id = ?`,
 		string(task.StateQueued), string(configJSON), now, id); err != nil {
 		return nil, err
 	}
diff --git a/internal/storage/db_test.go b/internal/storage/db_test.go
index d28a4a8..2956be0 100644
--- a/internal/storage/db_test.go
+++ b/internal/storage/db_test.go
@@ -628,6 +628,41 @@ func TestDeleteTask_DeepSubtaskCascadeAtomic(t *testing.T) {
 	}
 }
 
+// TestResetTaskForRetry_ClearsQuestionJSON verifies that restarting a BLOCKED
+// or FAILED task via ResetTaskForRetry clears any stale question so the frontend
+// does not show a stale "waiting for input" prompt.
+func TestResetTaskForRetry_ClearsQuestionJSON(t *testing.T) {
+	db := testDB(t)
+	now := time.Now().UTC()
+	tk := makeTestTask("retry-task", now)
+	tk.State = task.StatePending
+	db.CreateTask(tk)
+
+	// Transition to BLOCKED with a question.
+	db.UpdateTaskState("retry-task", task.StateQueued)
+	db.UpdateTaskState("retry-task", task.StateRunning)
+	db.UpdateTaskState("retry-task", task.StateBlocked)
+	db.UpdateTaskQuestion("retry-task", `{"question":"which branch?"}`)
+
+	// Simulate the task failing and being restarted.
+	db.UpdateTaskState("retry-task", task.StateFailed)
+
+	if _, err := db.ResetTaskForRetry("retry-task"); err != nil {
+		t.Fatalf("ResetTaskForRetry: %v", err)
+	}
+
+	got, err := db.GetTask("retry-task")
+	if err != nil {
+		t.Fatalf("GetTask: %v", err)
+	}
+	if got.QuestionJSON != "" {
+		t.Errorf("question_json should be cleared after reset, got %q", got.QuestionJSON)
+	}
+	if got.State != task.StateQueued {
+		t.Errorf("state should be QUEUED, got %q", got.State)
+	}
+}
+
 func TestStorage_GetLatestExecution(t *testing.T) {
 	db := testDB(t)
 	now := time.Now().UTC()