feat(ux): epic UX design improvements across agents, chat, notes, and i18n

Comprehensive UI/UX updates including agent card redesign, chat container
improvements, note editor enhancements, memory echo notifications, and
updated translations for all 15 locales.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

keep-notes/components/note-card.tsx

@@ -462,6 +462,21 @@ export const NoteCard = memo(function NoteCard({
         />
       )}
 
+      {/* Fusion Badge */}
+      {optimisticNote.aiProvider === 'fusion' && (
+        <div className="px-1.5 py-0.5 rounded text-[10px] font-medium bg-purple-100 dark:bg-purple-900/30 text-purple-700 dark:text-purple-400 border border-purple-200 dark:border-purple-800 flex items-center gap-1 group/badge relative mb-2 w-fit">
+          <Link2 className="h-2.5 w-2.5" />
+          {t('memoryEcho.fused')}
+          <button
+            onClick={handleRemoveFusedBadge}
+            className="ml-1 opacity-0 group-hover/badge:opacity-100 hover:opacity-100 transition-opacity"
+            title={t('notes.remove') || 'Remove'}
+          >
+            <Trash2 className="h-2.5 w-2.5" />
+          </button>
+        </div>
+      )}
+
       {/* Title */}
       {optimisticNote.title && (
         <h3 className="text-base font-medium mb-2 pr-10 text-foreground">
@@ -684,6 +699,7 @@ export const NoteCard = memo(function NoteCard({
                 type: 'text',
                 isMarkdown: true,
                 autoGenerated: true,
+                aiProvider: 'fusion',
                 notebookId: fusionNotes[0].notebookId ?? undefined
               })
               if (options.archiveOriginals) {