add userprofile routes, edited profile controller

[BenOkojie]

Closes #102

Summary

• Added authenticated routes for viewing and updating the current user’s profile
• Implemented get/update endpoints for user preferences
• All profile routes are protected via auth middleware

Endpoints

• GET /api/users/profile
• PUT /api/users/profile
• GET /api/users/preferences
• PUT /api/users/preferences

Notes

• Profile image upload endpoint was not implemented (optional requirement)
• Password update is handled via existing auth routes