feat(credits): solde IA unique (option M), packs Stripe et polish billing

Un pot de crédits global (BASIC 100 / PRO 1 000 / BUSINESS 4 000) remplace
les seaux par fonction côté débit. Packs one-shot S/M/L, admin sans seaux
legacy, usage multi-features, hints de coût, anti-flash thème et hydratation
admin. Inclut aussi le pipeline slides renforcé et la page publique polishée.

memento-note/app/(main)/layout.tsx

@@ -35,13 +35,13 @@ export default async function MainLayout({
       initialTranslations={initialTranslations}
       initialAiProcessingConsent={aiSettings?.aiProcessingConsent === true}
     >
-      {/* No top-bar header — sidebar-only navigation (architectural-grid design) */}
-      <div className="flex h-screen overflow-hidden bg-memento-desk dark:bg-background">
-        <Suspense fallback={<div className="hidden w-80 md:w-[26rem] 2xl:w-[30rem] shrink-0 md:block h-full self-stretch" />}>
+      {/* Fond via --background (suit .dark) — évite le flash beige/clair au changement de route */}
+      <div className="flex h-screen overflow-hidden bg-background">
+        <Suspense fallback={<div className="hidden w-80 md:w-[26rem] 2xl:w-[30rem] shrink-0 md:block h-full self-stretch bg-sidebar" />}>
           <Sidebar user={session?.user} />
         </Suspense>
 
-        <main className="flex min-h-0 flex-1 flex-col overflow-y-auto scroll-smooth bg-memento-paper dark:bg-background" id="main-content">
+        <main className="flex min-h-0 flex-1 flex-col overflow-y-auto scroll-smooth bg-background" id="main-content">
           <a href="#main-content" className="sr-only focus:not-sr-only focus:absolute focus:z-[9999] focus:top-2 focus:left-2 focus:bg-brand-accent focus:text-white focus:px-4 focus:py-2 focus:rounded-lg focus:text-sm focus:font-bold">
             Skip to content
           </a>

memento-note/app/(main)/settings/appearance/appearance-settings-client.tsx

@@ -6,7 +6,7 @@ import { updateUserSettings } from '@/app/actions/user-settings'
 import { useLanguage } from '@/lib/i18n'
 import { toast } from 'sonner'
 import { Palette, Type, LayoutGrid, Maximize } from 'lucide-react'
-import { applyDocumentTheme, normalizeThemeId, type ThemeId } from '@/lib/apply-document-theme'
+import { persistThemePreference, normalizeThemeId, type ThemeId } from '@/lib/apply-document-theme'
 import {
   NOTES_LAYOUT_STORAGE_KEY,
   parseNotesLayoutMode,
@@ -65,8 +65,7 @@ export function AppearanceSettingsClient({
   const handleThemeChange = async (value: string) => {
     const next = normalizeThemeId(value)
     setTheme(next)
-    localStorage.setItem('theme-preference', next)
-    applyDocumentTheme(next)
+    persistThemePreference(next)
     await updateUserSettings({ theme: next })
     toast.success(t('settings.settingsSaved'))
   }

memento-note/app/(main)/template.tsx

@@ -1,16 +1,12 @@
-'use client'
-
-import { motion } from 'motion/react'
-
+/**
+ * Plus d’animation d’entrée (opacity / translate) :
+ * ça laissait voir le fond clair une fraction de seconde en mode sombre.
+ * Conteneur neutre uniquement.
+ */
 export default function MainTemplate({ children }: { children: React.ReactNode }) {
   return (
-    <motion.div
-      initial={{ opacity: 0, x: 20 }}
-      animate={{ opacity: 1, x: 0 }}
-      transition={{ duration: 0.3 }}
-      className="flex-1 flex flex-col min-h-0"
-    >
+    <div className="flex min-h-0 flex-1 flex-col bg-background text-foreground">
       {children}
-    </motion.div>
+    </div>
   )
 }