refactor: remove obsolete scaffolding and dead modules

Drop the unused root hello-world controller, empty CommonModule imports, development seeding code, legacy student report entity, stale DTOs, notification hook, and their placeholder tests.

apps/server/src/deposits/deposits.module.ts

@@ -4,13 +4,12 @@ import { Student } from '../entities/student.entity';
 import { Deposit } from '../entities/deposit.entity';
 import { DepositInstallment } from '../entities/deposit-installment.entity';
 import { DepositsService } from './deposits.service';
-import { CommonModule } from '../common/common.module';
 import { DepositsController } from './deposits.controller';
 import { OperationLogsModule } from '../operation-logs/operation-logs.module';
 import { NotificationsModule } from '../notifications/notifications.module';
 
 @Module({
-  imports: [TypeOrmModule.forFeature([Deposit, DepositInstallment, Student]), OperationLogsModule, NotificationsModule, CommonModule],
+  imports: [TypeOrmModule.forFeature([Deposit, DepositInstallment, Student]), OperationLogsModule, NotificationsModule],
   controllers: [DepositsController],
   providers: [DepositsService],
   exports: [DepositsService],

apps/server/src/deposits/dto/deposit.dto.ts

@@ -24,15 +24,6 @@ export class CreateInstallmentDto {
   dueDate: string;
 }
 
-export class UpdateInstallmentDto {
-  @IsOptional()
-  @IsString()
-  paidDate?: string;
-
-  @IsOptional()
-  @IsString()
-  status?: string;
-}
 
 
 export class RefundDepositDto {
@@ -57,9 +48,3 @@ export class CreateDepositWithInstallmentsDto extends CreateDepositDto {
   @Type(() => CreateInstallmentDto)
   installments?: CreateInstallmentDto[];
 }
-
-export class ApproveRefundDto {
-  @IsOptional()
-  @IsString()
-  notes?: string;
-}