Apply the CREATE form's knobs to the photo in realtime

Every row now feeds the open render as it is typed, so a recipe's effect is
visible before it is saved. The draft is not an undo step: SAVE/EXPORT stays the
only thing that commits it, and merely opening the tab changes nothing.

docker/frontend/src/App.tsx

@@ -324,6 +324,13 @@ export function Workspace() {
     [user, applyRecipe, t]
   );
 
+  // CREATE edits the photo live: each knob lands on the render as it is typed so
+  // the recipe can be judged before saving. No undo entry — this is a draft, and
+  // SAVE/EXPORT is what commits it.
+  const previewCreatedRecipe = useCallback((draft: Pick<Recipe, 'baseFilter' | 'adjustments'>) => {
+    setRecipe((prev) => ({ ...prev, ...draft, isCustom: true }));
+  }, []);
+
   // The phone's encrypted .recipe envelope (`shared/utils/recipeShare` is the
   // app's own file, byte-identical). Signed in only — a guest's recipe is never
   // written to disk.
@@ -781,6 +788,7 @@ export function Workspace() {
               currentBase={recipe.baseFilter}
               current={recipe.adjustments}
               signedIn={!!user}
+              onPreview={previewCreatedRecipe}
               onSave={(draft) => void addCreatedRecipe(draft)}
               onExport={exportRecipeFile}
             />