feat: notes encore plus larges — max-w-6xl body + font 18px

Full page editor:
- Container: max-w-5xl → max-w-6xl (1024px → 1152px)
- Content: max-w-4xl → max-w-5xl (896px → 1024px)
- Toolbar: max-w-5xl → max-w-6xl (aligné)

Dialog editor:
- max-w 1800px → 2000px, 97vw → 98vw
- Hauteur 92vh → 94vh

Font editor:
- editor-body-size: 16px → 18px (lecture plus confortable)

memento-note/components/note-editor/note-editor-dialog.tsx

@@ -46,7 +46,7 @@ export function NoteEditorDialog({ onClose }: NoteEditorDialogProps) {
     <Dialog open={true} onOpenChange={onClose}>
       <DialogContent
         className={cn(
-          '!max-w-[min(97vw,1800px)] h-[92vh] overflow-hidden p-0 flex flex-row items-stretch rounded-lg',
+          '!max-w-[min(98vw,2000px)] h-[94vh] overflow-hidden p-0 flex flex-row items-stretch rounded-lg',
           state.colorClasses
         )}
       >