User Story: Increase bcrypt cost factor in src/javascript/backend/auth/authentication.js

[aliAljaffer]

As a developer
I want to use a stronger bcrypt cost factor when hashing passwords in src/javascript/backend/auth/authentication.js
So that user passwords are hashed with sufficient work factor to resist brute-force attacks

Acceptance Criteria

• Replace bcrypt.hash(password, 8) with a configurable, stronger cost (e.g. 12 or higher) or use an environment-configured value.
• Add a comment explaining why the chosen cost is appropriate and how to tune it.
• Run a basic test demonstrating hashing and verification still succeed.

Details
Found: const hashedPassword = await bcrypt.hash(password, 8); (insufficient rounds). This is a security weakness in the JS. Adjust the cost and make it configurable.