Address #128 review: doc lines and an exact position assertion

Co-Authored-By: Claude Fable 5 <[email protected]>

internal/service/ops_test.go

@@ -628,14 +628,20 @@ func TestDescribeGardenGroupsByPlant(t *testing.T) {
 	if want := 2*derivedCount(20, 25) + 3; ba.Plants != want {
 		t.Errorf("basil plants = %d, want %d", ba.Plants, want)
 	}
+	// The position is what lets a move keep the layout; "south" alone can't. The
+	// three basil plops were placed at exactly these local points.
+	placedAt := map[[2]float64]bool{{-100, 100}: true, {0, 150}: true, {100, 100}: true}
 	for _, e := range ba.Each {
 		if e.PlantedAt == "" || e.Version == 0 || e.ID == 0 {
 			t.Errorf("listed plop %+v is missing id, version or date", e)
 		}
-		// The position is what lets a move keep the layout; "south" alone can't.
-		if e.YCM < 100 || (e.XCM != -100 && e.XCM != 0 && e.XCM != 100) {
-			t.Errorf("listed plop %+v doesn't carry the position it was placed at", e)
+		if !placedAt[[2]float64{e.XCM, e.YCM}] {
+			t.Errorf("listed plop %+v is not at a position a basil was placed at", e)
 		}
+		delete(placedAt, [2]float64{e.XCM, e.YCM})
+	}
+	if len(placedAt) != 0 {
+		t.Errorf("positions never listed: %v", placedAt)
 	}
 
 	// The big group's ids are a call away, narrowed to one plant.