chore: sync schema with scrum4me@7461643 (M9 + M10)

Bumps vendor/scrum4me submodule from 43a4294 (ST-509/511/512/513) naar 7461643
en daarmee picks de schema-wijzigingen op uit:
- M8 (ST-801): notify_solo_change-trigger op tasks/stories
- M9 (ST-901): User.active_product_id + UserActiveProduct relation
- M10 (ST-1001): LoginPairing model + login_pairings_notify-trigger op
  scrum4me_pairing channel; User.login_pairings back-relation

Verificatie: npm run sync-schema + npm run prisma:generate + npm run typecheck
allemaal groen. Sluit de wekelijkse drift-check (trig_015FFUnxjz9WMuhhWNGBQKFD)
voor deze drie milestones.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

prisma/schema.prisma

@@ -51,6 +51,8 @@ model User {
   bio               String?         @db.VarChar(160)
   bio_detail        String?         @db.VarChar(2000)
   avatar_data       Bytes?
+  active_product_id String?
+  active_product    Product?        @relation("UserActiveProduct", fields: [active_product_id], references: [id], onDelete: SetNull)
   created_at        DateTime        @default(now())
   updated_at        DateTime        @updatedAt
   roles             UserRole[]
@@ -59,7 +61,9 @@ model User {
   todos             Todo[]
   product_members   ProductMember[]
   assigned_stories  Story[]         @relation("StoryAssignee")
+  login_pairings    LoginPairing[]
 
+  @@index([active_product_id])
   @@map("users")
 }
 
@@ -103,6 +107,7 @@ model Product {
   stories            Story[]
   todos              Todo[]
   members            ProductMember[]
+  active_for_users   User[]          @relation("UserActiveProduct")
 
   @@unique([user_id, name])
   @@unique([user_id, code])
@@ -239,3 +244,22 @@ model Todo {
   @@index([user_id, product_id])
   @@map("todos")
 }
+
+model LoginPairing {
+  id                 String    @id @default(cuid())
+  secret_hash        String
+  desktop_token_hash String
+  status             String
+  user_id            String?
+  user               User?     @relation(fields: [user_id], references: [id], onDelete: SetNull)
+  desktop_ua         String?   @db.VarChar(255)
+  desktop_ip         String?   @db.VarChar(45)
+  created_at         DateTime  @default(now())
+  expires_at         DateTime
+  approved_at        DateTime?
+  consumed_at        DateTime?
+
+  @@index([expires_at])
+  @@index([status, expires_at])
+  @@map("login_pairings")
+}

vendor/scrum4me

@@ -1 +1 @@
-Subproject commit 43a429442491c29148c921fa2943960f70dd9fb6
+Subproject commit 74616432d25dfbee706de1eb80b338e3d7433764