feat: smart note history with manual/auto modes, delete entries, i18n fixes

- Add noteHistoryMode setting (manual default / auto) with DB migration
- Manual mode: commit button in editor toolbar creates snapshots on demand
- Auto mode: smart snapshots with 20-char diff threshold + 5min cooldown,
  structural changes (color, pin, archive, labels) bypass cooldown
- Add delete individual history entries from history modal
- Fix sidebar: Notes nav no longer active on notebook pages
- Fix sidebar icon: replace filled Lightbulb with outlined FileText
- Fix title suggestions: change from amber to sky blue color scheme
- Fix hydration mismatch: add suppressHydrationWarning on locale dates
- Complete i18n: add history, sort, and AI chat translations for all 16 languages
- Translate French AI assistant section (40+ keys) from English to French
- Update README with new features and stack info

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

memento-note/components/title-suggestions.tsx

@@ -15,16 +15,16 @@ export function TitleSuggestions({ suggestions, onSelect, onDismiss }: TitleSugg
   if (suggestions.length === 0) return null
 
   return (
-    <div className="mt-2 p-3 bg-amber-50 dark:bg-amber-950 border border-amber-200 dark:border-amber-800 rounded-lg animate-in fade-in slide-in-from-top-2 duration-300">
+    <div className="mt-2 p-3 bg-sky-50 dark:bg-sky-950/50 border border-sky-200 dark:border-sky-800 rounded-lg animate-in fade-in slide-in-from-top-2 duration-300">
       <div className="flex items-center justify-between mb-2">
-        <div className="flex items-center gap-2 text-sm font-medium text-amber-900 dark:text-amber-100">
+        <div className="flex items-center gap-2 text-sm font-medium text-sky-900 dark:text-sky-100">
           <Sparkles className="w-4 h-4" />
           <span>{t('titleSuggestions.title')}</span>
         </div>
         <button
           type="button"
           onClick={onDismiss}
-          className="text-amber-600 hover:text-amber-900 dark:text-amber-400 dark:hover:text-amber-200 transition-colors"
+          className="text-sky-500 hover:text-sky-900 dark:text-sky-400 dark:hover:text-sky-200 transition-colors"
         >
           <X className="w-4 h-4" />
         </button>
@@ -38,19 +38,19 @@ export function TitleSuggestions({ suggestions, onSelect, onDismiss }: TitleSugg
             onClick={() => onSelect(suggestion.title)}
             className={cn(
               "w-full text-left px-3 py-2 rounded-md transition-all",
-              "hover:bg-amber-100 dark:hover:bg-amber-900",
-              "text-sm text-amber-900 dark:text-amber-100",
-              "border border-transparent hover:border-amber-300 dark:hover:border-amber-700"
+              "hover:bg-sky-100 dark:hover:bg-sky-900/50",
+              "text-sm text-sky-900 dark:text-sky-100",
+              "border border-transparent hover:border-sky-300 dark:hover:border-sky-700"
             )}
           >
             <div className="flex items-start justify-between gap-2">
               <span className="font-medium">{suggestion.title}</span>
-              <span className="text-xs text-amber-600 dark:text-amber-400 whitespace-nowrap">
+              <span className="text-xs text-sky-500 dark:text-sky-400 whitespace-nowrap">
                 {suggestion.confidence}%
               </span>
             </div>
             {suggestion.reasoning && (
-              <p className="text-xs text-amber-700 dark:text-amber-300 mt-1">
+              <p className="text-xs text-sky-600 dark:text-sky-300 mt-1">
                 {suggestion.reasoning}
               </p>
             )}