fix: secure password storage and authentication using bcrypt

[tylrx404]

Summary

This PR fixes a security vulnerability where user passwords were stored and compared in plain text.

Changes Made

• Added bcrypt password hashing during user registration.
• Replaced plain-text password comparison with bcrypt.compare() during login.
• Updated authentication flow to use secure password verification.
• Preserved existing authentication behavior and error handling.

Testing

• Verified successful account creation with hashed password storage.
• Verified login succeeds with correct credentials.
• Verified login fails with incorrect credentials.
• Confirmed passwords are no longer stored in plain text in the database.

Fixes #1179