feat: integrate Swagger OpenAPI documentation

[hashhhh-16]

Summary

Integrated Swagger/OpenAPI documentation into the backend to provide centralized, interactive API documentation for contributors and developers.

Changes Made

• Added swagger-ui-express and swagger-jsdoc

• Configured Swagger UI at /api-docs

• Added OpenAPI 3.0 specification setup in server.js

• Documented Authentication endpoints:

  • POST /api/auth/register
  • POST /api/auth/login
  • POST /api/auth/forgot-password
  • POST /api/auth/reset-password

• Documented Notice endpoints:

  • GET /api/notices
  • POST /api/notices

• Organized endpoints using Swagger tags for easier navigation

Testing

• Verified Swagger UI loads successfully at /api-docs
• Verified Authentication endpoints appear correctly in the documentation
• Verified Notice endpoints appear correctly in the documentation
• Confirmed endpoint grouping and request/response documentation are rendered properly

Acceptance Criteria Checklist

• Swagger/OpenAPI is successfully integrated into the backend
• API documentation is accessible through a dedicated route
• Core endpoints are documented with request and response details
• Authentication-related endpoints are clearly documented
• Documentation is easy to navigate and maintain

Closes #106