feat(admin): consentement aux annonces et désabonnement sans connexion

Les comptes déjà créés ne sont pas inscrits. Le choix est facultatif à l’inscription et dans les paramètres. Un lien public demande confirmation avant d’arrêter les actualités, sans toucher aux messages de compte.

memento-note/prisma/schema.prisma

@@ -54,6 +54,8 @@ model User {
   usageLogs             UsageLog[]
   apiKeys               UserAPIKey[]
   aiConsentLogs         AiConsentLog[]
+  marketingPreference   MarketingPreference?
+  emailSuppressions     EmailSuppression[]
   noteClusters          NoteCluster[]
   bridgeNotes           BridgeNote[]
   bridgeSuggestions     BridgeSuggestion[]
@@ -1124,3 +1126,55 @@ model ErrorLog {
   @@index([createdAt])
   @@index([resolved])
 }
+
+/// Explicit marketing announcements opt-in. Missing row = not opted in.
+model MarketingPreference {
+  id                String                     @id @default(cuid())
+  userId            String                     @unique
+  emailNormalized   String
+  optedIn           Boolean                    @default(false)
+  preferredLanguage String?
+  consentVersion    String?
+  consentText       String?                    @db.Text
+  source            String
+  createdAt         DateTime                   @default(now())
+  updatedAt         DateTime                   @updatedAt
+  user              User                       @relation(fields: [userId], references: [id], onDelete: Cascade)
+  events            MarketingPreferenceEvent[]
+
+  @@index([emailNormalized])
+  @@index([optedIn])
+}
+
+model MarketingPreferenceEvent {
+  id                String              @id @default(cuid())
+  preferenceId      String
+  userId            String?
+  emailNormalized   String
+  optedIn           Boolean
+  source            String
+  consentVersion    String?
+  consentText       String?             @db.Text
+  ip                String?
+  userAgent         String?
+  createdAt         DateTime            @default(now())
+  preference        MarketingPreference @relation(fields: [preferenceId], references: [id], onDelete: Cascade)
+
+  @@index([preferenceId])
+  @@index([userId, createdAt])
+  @@index([emailNormalized, createdAt])
+}
+
+/// Blocks campaign mail. Kept after account deletion (userId set null).
+model EmailSuppression {
+  id              String   @id @default(cuid())
+  emailNormalized String   @unique
+  reason          String
+  source          String
+  userId          String?
+  createdAt       DateTime @default(now())
+  user            User?    @relation(fields: [userId], references: [id], onDelete: SetNull)
+
+  @@index([reason])
+  @@index([userId])
+}