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}
             />

docker/frontend/src/ui/RecipeCreatePanel.tsx

@@ -1,4 +1,4 @@
-import { useState } from 'react';
+import { useEffect, useRef, useState } from 'react';
 import { ChipRow, type ChipDef } from './ChipColumn';
 import { useI18n } from '../i18n/I18nProvider';
 import { DEFAULT_ADJUSTMENTS, FILM_SIMS } from '../../shared/utils/defaultRecipes';
@@ -55,12 +55,14 @@ export function RecipeCreatePanel({
   currentBase,
   current,
   signedIn,
+  onPreview,
   onSave,
   onExport,
 }: {
   currentBase?: BaseFilter;
   current?: ColorAdjustments | null;
   signedIn: boolean;
+  onPreview: (draft: Pick<Recipe, 'baseFilter' | 'adjustments'>) => void;
   onSave: (draft: RecipeDraft) => void;
   onExport: (draft: RecipeDraft) => void;
 }) {
@@ -153,6 +155,20 @@ export function RecipeCreatePanel({
     return { name: name.trim() || 'NEW RECIPE', baseFilter: sim, adjustments, frameId: 'none', useGeotag: true };
   };
 
+  // Realtime: every knob applies to the photo on screen as it is typed, so the
+  // effect of the recipe is visible before saving it. Opening the tab is not an
+  // edit — the first run (the seeded values) is skipped.
+  const first = useRef(true);
+  useEffect(() => {
+    if (first.current) {
+      first.current = false;
+      return;
+    }
+    const { baseFilter, adjustments } = build();
+    onPreview({ baseFilter, adjustments });
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [sim, dr, grain, cc, ccb, wbKey, wbRed, wbBlue, fHigh, fShadow, fColor, fNr, fSharp, fClarity, fEv]);
+
   const opts = (
     prefix: string,
     options: { v: string; d: string }[],