Find the canvas tools by the condition they are gated on now

The download fix renamed the canvas gates to root.has-photo, and the
canvas-order test still searched for the old spelling, so it panicked
before checking anything. The order it guards is unchanged.

ui/dr-ui/src/masks_ui.rs

@@ -1877,8 +1877,8 @@ mod canvas_order {
         for tool in [
             "pick := TouchArea",
             "paint := TouchArea",
-            "Develop.repairing && root.total > 0",
-            "root.sampling && root.total > 0",
+            "Develop.repairing && root.has-photo",
+            "root.sampling && root.has-photo",
         ] {
             assert!(
                 pan < at(tool),