Add the CREATE RECIPES tab to the web app

The phone's RecipeCreateModal becomes a rail tab with the same rows, seeding
from the look on screen and clamping the same way. SAVE RECIPE applies the new
look, lists it under RECIPES and, when signed in, stores it on the account; a
guest's copy stays in memory and goes away with the page. Signed-in users can
also export the recipe as the app's encrypted .recipe file (shared/utils
/recipeShare.ts vendored byte-identical from the RN project).

docker/frontend/src/ui/ToolRail.tsx

@@ -3,7 +3,7 @@ import { useI18n } from '../i18n/I18nProvider';
 
 // The app's six tabs, in the same order as the phone rail. The rail is vertical
 // on desktop and becomes the bottom bar under 860px (see styles/app.css).
-export type TabId = 'presets' | 'favorited' | 'light' | 'wb' | 'fx' | 'frame';
+export type TabId = 'presets' | 'favorited' | 'light' | 'wb' | 'fx' | 'frame' | 'create';
 
 export const TABS: { id: TabId; label: MsgKey; glyph: string }[] = [
   { id: 'presets', label: 'tab.presets', glyph: '◉' },
@@ -12,6 +12,7 @@ export const TABS: { id: TabId; label: MsgKey; glyph: string }[] = [
   { id: 'wb', label: 'tab.wb', glyph: '◐' },
   { id: 'fx', label: 'tab.fx', glyph: '✦' },
   { id: 'frame', label: 'tab.frame', glyph: '▣' },
+  { id: 'create', label: 'tab.create', glyph: '✎' },
 ];
 
 export function ToolRail({ tab, onTab }: { tab: TabId; onTab: (tab: TabId) => void }) {