refactor: RF-03/06 extract groupMeals helper, eliminate convertSyncItemToTask wrapper

RF-03: Extract shared groupMeals helper into internal/handlers/meals.go.
Both HandleTabMeals and BuildTimeline now call groupMeals instead of
duplicating the date+mealType grouping algorithm inline. CombinedMeal
gains ID and Meals fields to carry the first-meal ID and original records
needed by BuildTimeline when constructing TimelineItems.

RF-06: Add api.ConvertSyncItemToTask for single-item conversion.
ConvertSyncItemsToTasks now delegates to it, eliminating duplication.
The Handler.convertSyncItemToTask wrapper (which allocated a one-element
slice just to unwrap it) is deleted; its caller uses api.ConvertSyncItemToTask
directly. Covered by TestConvertSyncItemToTask in internal/api/todoist_test.go.

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

1 files changed, 51 insertions, 0 deletions

diff --git a/internal/api/todoist_test.go b/internal/api/todoist_test.go
index 159be61..2204469 100644
--- a/internal/api/todoist_test.go
+++ b/internal/api/todoist_test.go
@@ -421,6 +421,57 @@ func TestConvertSyncItemsToTasks(t *testing.T) {
 	}
 }
 
+func TestConvertSyncItemToTask(t *testing.T) {
+	projects := map[string]string{"proj-1": "Project 1"}
+
+	t.Run("active item returns task and true", func(t *testing.T) {
+		item := SyncItemResponse{
+			ID:          "item-1",
+			Content:     "Active Task",
+			Description: "desc",
+			ProjectID:   "proj-1",
+			Priority:    2,
+			Labels:      []string{"work"},
+			AddedAt:     "2026-01-01T00:00:00Z",
+		}
+		task, ok := ConvertSyncItemToTask(item, projects)
+		if !ok {
+			t.Fatal("expected ok=true for active item")
+		}
+		if task.ID != "item-1" {
+			t.Errorf("expected ID 'item-1', got '%s'", task.ID)
+		}
+		if task.Content != "Active Task" {
+			t.Errorf("expected Content 'Active Task', got '%s'", task.Content)
+		}
+		if task.ProjectName != "Project 1" {
+			t.Errorf("expected ProjectName 'Project 1', got '%s'", task.ProjectName)
+		}
+		if task.Completed {
+			t.Error("expected Completed=false")
+		}
+		if task.URL != "https://todoist.com/app/task/item-1" {
+			t.Errorf("unexpected URL: %s", task.URL)
+		}
+	})
+
+	t.Run("completed item returns false", func(t *testing.T) {
+		item := SyncItemResponse{ID: "item-2", Content: "Done", ProjectID: "proj-1", IsCompleted: true}
+		_, ok := ConvertSyncItemToTask(item, projects)
+		if ok {
+			t.Error("expected ok=false for completed item")
+		}
+	})
+
+	t.Run("deleted item returns false", func(t *testing.T) {
+		item := SyncItemResponse{ID: "item-3", Content: "Gone", ProjectID: "proj-1", IsDeleted: true}
+		_, ok := ConvertSyncItemToTask(item, projects)
+		if ok {
+			t.Error("expected ok=false for deleted item")
+		}
+	})
+}
+
 func TestBuildProjectMapFromSync(t *testing.T) {
 	projects := []SyncProjectResponse{
 		{ID: "proj-1", Name: "Project 1"},