Title: Convert all controllers to ES6 module syntax

[agaesh]

🧩 Issue : Convert Controllers to ES6 Module Syntax

Description

Refactor all controller files to use ES6 import / export syntax instead of CommonJS require / module.exports.
This change ensures compatibility with ViteJS and Supertest, which depend on native ES module support.

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Controllers

• DepartmentController
• InstructorController
• ProgramCourseController
• SemesterController
• UserController

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Tasks

• Replace require → import
• Replace module.exports → export

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Branch

fix/es6-Controllers

[agaesh]

All controllers have been successfully migrated to ES6 module syntax and verified for compatibility with the refactored models and modern Node.js environment.
This update standardizes import/export usage across the backend and improves maintainability for future enhancements.

Tracking completed under: fix/es6-controllers
Closing this issue.