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/lib/interactive-page/constants.ts

@@ -8,7 +8,7 @@ export const INTERACTIVE_PAGE_CAPS = {
   maxDemosPerPage: 5,
   maxSimsPerPage: 3,
   maxOverviewCards: 4,
-  minOverviewCards: 2,
+  minOverviewCards: 3,
   maxStatsItems: 5,
   minStatsItems: 2,
   maxJsonBytes: 128 * 1024,
@@ -30,8 +30,14 @@ export const PAGE_BLOCK_TYPES = [
   'table',
   'image',
   'sim',
+  'steps',
 ] as const
 
+export const STEPS_CAPS = {
+  minSteps: 2,
+  maxSteps: 12,
+} as const
+
 export const CALLOUT_KINDS = [
   'definition',
   'warning',
@@ -69,6 +75,8 @@ export const PAGE_HUMAN_STRING_KEYS = [
   'intro',
   'xLabel',
   'yLabel',
+  // steps blocks
+  'rule',
   // inherited from demos (speak etc. scanned via demo validator)
   'speak',
   'text',