feat: dashboard Second Brain, essai 7 jours et vérification e-mail

Rendre le dashboard actionnable (inbox, peek, carte mentale), aligner la facturation sur l’essai 7 jours, et bloquer le login e-mail tant que l’adresse n’est pas confirmée.

Co-authored-by: Cursor <cursoragent@cursor.com>

memento-note/components/interactive-page/page-md.tsx

@@ -31,7 +31,8 @@ export function PageMd({
 
     let out = marked.parse(withSlots, { gfm: true, breaks: true }) as string
     placeholders.forEach((frag, i) => {
-      out = out.replace(`%%KATEX${i}%%`, frag)
+      // function replacement — $', $`, $& in KaTeX HTML must not be interpreted
+      out = out.replace(`%%KATEX${i}%%`, () => frag)
     })
     return sanitizeRichHtml(out)
   }, [md])