Add task title editing/deletion, timeline click-to-open, widget app launch

Task-detail modal was description-only with no delete affordance;
HandleUpdateTask now saves the title too and a Delete button hits a new
DELETE /tasks/{id} route backed by store.DeleteNativeTask, which repairs
chain_position/unlocks the successor when the deleted task belongs to a
chain. Timeline tab task/card/gtask rows now open the same detail modal
as the Tasks tab. Android widget's "TODAY" header is now a tap target
that launches DashboardActivity, since nothing previously opened the
full app from the widget.

1 files changed, 20 insertions, 0 deletions

diff --git a/internal/store/native_tasks_test.go b/internal/store/native_tasks_test.go
index d82576e..9a7e55f 100644
--- a/internal/store/native_tasks_test.go
+++ b/internal/store/native_tasks_test.go
@@ -698,3 +698,23 @@ func TestCreateNextIteration_CarriesEstimatedMinutesForward(t *testing.T) {
 		t.Errorf("EstimatedMinutes = %d, want 60 (carried forward)", next.EstimatedMinutes)
 	}
 }
+
+func TestDeleteNativeTask_PlainTask_Removed(t *testing.T) {
+	s := newNativeTasksTestStore(t)
+
+	if err := s.DeleteNativeTask("real-1"); err != nil {
+		t.Fatalf("DeleteNativeTask: %v", err)
+	}
+
+	if _, err := s.GetNativeTaskByID("real-1"); !errors.Is(err, ErrNativeTaskNotFound) {
+		t.Errorf("err = %v, want ErrNativeTaskNotFound", err)
+	}
+}
+
+func TestDeleteNativeTask_UnknownID_ReturnsErrNotFound(t *testing.T) {
+	s := newNativeTasksTestStore(t)
+
+	if err := s.DeleteNativeTask("does-not-exist"); !errors.Is(err, ErrNativeTaskNotFound) {
+		t.Errorf("err = %v, want ErrNativeTaskNotFound", err)
+	}
+}