feat(task1): restructure directories for turborepo monorepo

- Move backend/ to apps/server/ via git mv
- Move frontend/ to apps/admin/ via git mv
- Create packages/typescript-config/ with base, nestjs, and react-vite presets

apps/server/src/students/students.module.ts

@@ -0,0 +1,13 @@
+import { Module } from '@nestjs/common';
+import { TypeOrmModule } from '@nestjs/typeorm';
+import { Student } from '../entities/student.entity';
+import { StudentsService } from './students.service';
+import { StudentsController } from './students.controller';
+
+@Module({
+  imports: [TypeOrmModule.forFeature([Student])],
+  controllers: [StudentsController],
+  providers: [StudentsService],
+  exports: [StudentsService],
+})
+export class StudentsModule {}