updated bucket settings page

prisma/schema.prisma

@@ -546,3 +546,12 @@ model ReviewSession {
 
   @@map("review_sessions")
 }
+
+/// Key-value store for system-wide configuration (e.g. storage credentials)
+model SystemConfig {
+  key       String   @id
+  value     String   @db.Text
+  updatedAt DateTime @updatedAt
+
+  @@map("system_config")
+}