feat: Implement user enrollment interaction to assign a random class role and add new role configurations.

src/db/schema.ts

@@ -21,6 +21,7 @@ export const classes = pgTable('classes', {
     id: bigint('id', { mode: 'bigint' }).primaryKey(),
     name: varchar('name', { length: 255 }).unique().notNull(),
     balance: bigint('balance', { mode: 'bigint' }).default(0n),
+    roleId: varchar('role_id', { length: 255 }),
 });
 
 // 2. Users