Fix blank task-detail modal for Google Tasks

loadTaskDetailData/HandleUpdateTask only had cases for "trello" and
"doot" sources, so opening a gtask from the Tasks or Timeline tab
rendered an empty title/description. Reuses the existing
findGoogleTask cache lookup for both. Renamed the API client's
UpdateTaskNotes to UpdateTask(title, notes) so the web modal can save
an edited title too, not just description; the widget's
description-only edit popup now just round-trips the task's existing
title unchanged.

4 files changed, 85 insertions, 3 deletions

diff --git a/internal/handlers/handlers.go b/internal/handlers/handlers.go
index 30aaf67..7220474 100644
--- a/internal/handlers/handlers.go
+++ b/internal/handlers/handlers.go
@@ -832,6 +832,10 @@ func (h *Handler) loadTaskDetailData(id, source string) taskDetailData {
 			data.RecurrenceInterval = task.RecurrenceInterval
 			data.RecurrenceWeekdays = task.RecurrenceWeekdays
 		}
+	case "gtasks":
+		if t, ok := h.findGoogleTask(id); ok {
+			data.Title, data.Description = t.Title, t.Notes
+		}
 	}
 	return data
 }
@@ -975,6 +979,24 @@ func (h *Handler) HandleUpdateTask(w http.ResponseWriter, r *http.Request) {
 			updates["name"] = title
 		}
 		err = h.trelloClient.UpdateCard(r.Context(), id, updates)
+	case "gtasks":
+		if h.googleTasksClient == nil {
+			JSONError(w, http.StatusServiceUnavailable, "Google Tasks not configured", nil)
+			return
+		}
+		t, ok := h.findGoogleTask(id)
+		if !ok {
+			JSONError(w, http.StatusNotFound, "task not found", nil)
+			return
+		}
+		saveTitle := title
+		if saveTitle == "" {
+			saveTitle = t.Title
+		}
+		err = h.googleTasksClient.UpdateTask(r.Context(), t.ListID, id, saveTitle, description)
+		if err == nil {
+			_ = h.store.InvalidateCache(store.CacheKeyGoogleTasks)
+		}
 	default:
 		JSONError(w, http.StatusBadRequest, "Unknown source", nil)
 		return
diff --git a/internal/handlers/handlers_test.go b/internal/handlers/handlers_test.go
index b618b71..8900f66 100644
--- a/internal/handlers/handlers_test.go
+++ b/internal/handlers/handlers_test.go
@@ -1965,6 +1965,62 @@ func TestHandleUpdateTask_DootSource_NoTitle_LeavesContentUntouched(t *testing.T
 	}
 }
 
+func TestHandleGetTaskDetail_GtasksSource_LoadsRealTaskFields(t *testing.T) {
+	h, cleanup := setupTestHandler(t)
+	defer cleanup()
+
+	if err := h.store.SaveGoogleTasks([]models.GoogleTask{
+		{ID: "g1", Title: "Renew passport", Notes: "bring photo", ListID: "list-a", UpdatedAt: time.Now()},
+	}); err != nil {
+		t.Fatal(err)
+	}
+
+	req := httptest.NewRequest("GET", "/tasks/detail?id=g1&source=gtasks", nil)
+	w := httptest.NewRecorder()
+	h.HandleGetTaskDetail(w, req)
+
+	if w.Code != http.StatusOK {
+		t.Fatalf("status = %d, want 200, body=%s", w.Code, w.Body.String())
+	}
+	mock := h.renderer.(*MockRenderer)
+	data, ok := mock.Calls[len(mock.Calls)-1].Data.(taskDetailData)
+	if !ok {
+		t.Fatalf("unexpected data type %T", mock.Calls[len(mock.Calls)-1].Data)
+	}
+	if data.Title != "Renew passport" || data.Description != "bring photo" {
+		t.Errorf("Title/Description = %q/%q, want %q/%q", data.Title, data.Description, "Renew passport", "bring photo")
+	}
+	if data.IsDoot {
+		t.Error("IsDoot = true, want false for a Google Task")
+	}
+}
+
+func TestHandleUpdateTask_GtasksSource_SavesTitleAndNotes(t *testing.T) {
+	h, cleanup := setupTestHandler(t)
+	defer cleanup()
+
+	if err := h.store.SaveGoogleTasks([]models.GoogleTask{
+		{ID: "g1", Title: "Old title", Notes: "Old notes", ListID: "list-a", UpdatedAt: time.Now()},
+	}); err != nil {
+		t.Fatal(err)
+	}
+	mock := &mockGoogleTasksClient{}
+	h.googleTasksClient = mock
+
+	req := httptest.NewRequest("POST", "/tasks/update", strings.NewReader("id=g1&source=gtasks&title=New+title&description=New+notes"))
+	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+	req.Header.Set("HX-Request", "true")
+	w := httptest.NewRecorder()
+	h.HandleUpdateTask(w, req)
+
+	if w.Code != http.StatusOK {
+		t.Fatalf("status = %d, want 200, body=%s", w.Code, w.Body.String())
+	}
+	if mock.notesListID != "list-a" || mock.notesTaskID != "g1" || mock.notesTitle != "New title" || mock.notes != "New notes" {
+		t.Errorf("unexpected update call: listID=%q taskID=%q title=%q notes=%q", mock.notesListID, mock.notesTaskID, mock.notesTitle, mock.notes)
+	}
+}
+
 func TestHandleDeleteTask_DootSource_RemovesTask(t *testing.T) {
 	h, cleanup := setupTestHandler(t)
 	defer cleanup()
diff --git a/internal/handlers/widget.go b/internal/handlers/widget.go
index 1f6911b..7557da1 100644
--- a/internal/handlers/widget.go
+++ b/internal/handlers/widget.go
@@ -367,7 +367,7 @@ func (h *Handler) HandleWidgetUpdate(w http.ResponseWriter, r *http.Request) {
 			http.Error(w, "task not found", http.StatusNotFound)
 			return
 		}
-		if err := h.googleTasksClient.UpdateTaskNotes(r.Context(), t.ListID, req.ID, req.Description); err != nil {
+		if err := h.googleTasksClient.UpdateTask(r.Context(), t.ListID, req.ID, t.Title, req.Description); err != nil {
 			http.Error(w, "failed to update task", http.StatusInternalServerError)
 			return
 		}
diff --git a/internal/handlers/widget_test.go b/internal/handlers/widget_test.go
index 2bb92bc..fcbba52 100644
--- a/internal/handlers/widget_test.go
+++ b/internal/handlers/widget_test.go
@@ -17,6 +17,7 @@ import (
 type mockGoogleTasksClient struct {
 	completedListID, completedTaskID string
 	notesListID, notesTaskID, notes  string
+	notesTitle                       string
 }
 
 func (m *mockGoogleTasksClient) GetTasks(ctx context.Context) ([]models.GoogleTask, error) {
@@ -32,8 +33,8 @@ func (m *mockGoogleTasksClient) CompleteTask(ctx context.Context, listID, taskID
 func (m *mockGoogleTasksClient) UncompleteTask(ctx context.Context, listID, taskID string) error {
 	return nil
 }
-func (m *mockGoogleTasksClient) UpdateTaskNotes(ctx context.Context, listID, taskID, notes string) error {
-	m.notesListID, m.notesTaskID, m.notes = listID, taskID, notes
+func (m *mockGoogleTasksClient) UpdateTask(ctx context.Context, listID, taskID, title, notes string) error {
+	m.notesListID, m.notesTaskID, m.notesTitle, m.notes = listID, taskID, title, notes
 	return nil
 }
 func (m *mockGoogleTasksClient) GetTaskLists(ctx context.Context) ([]models.TaskListInfo, error) {
@@ -678,6 +679,9 @@ func TestHandleWidgetUpdate_GoogleTask(t *testing.T) {
 	if mock.notesListID != "list-a" || mock.notesTaskID != "g1" || mock.notes != "bring photo and $170" {
 		t.Errorf("unexpected update call: listID=%q taskID=%q notes=%q", mock.notesListID, mock.notesTaskID, mock.notes)
 	}
+	if mock.notesTitle != "Renew passport" {
+		t.Errorf("title = %q, want unchanged %q (widget's edit popup has no title field)", mock.notesTitle, "Renew passport")
+	}
 }
 
 func seedTestCard(t *testing.T, db *store.Store) {