Canvas: align step label (Scene prompt -> Prompt)

app.py

@@ -475,7 +475,7 @@ SCRIPT = r"""
   const STEP_HINTS = [
     ["Aspect ratio","Pick the frame your scene lives in."],
     ["Elements","Drag out a box for every element that matters, then describe what goes in it."],
-    ["Scene prompt","Give the scene one line that ties the elements together."],
+    ["Prompt","One line describing the whole scene — or the edit, if you added a reference image."],
     ["Generate","FLUX.3 renders the scene with every element inside its box."],
   ];
   let S = {aspect:"1:1", elements:[], scene:"", seed:-1, rendered:false, step:1, showBoxes:true,