User Story: Replace insecure ID generation in src/javascript/shared/utils.js

[aliAljaffer]

As a developer
I want to replace insecure random ID generation in src/javascript/shared/utils.js with a cryptographically secure method
So that identifiers (e.g., session IDs, tokens) are not predictable and cannot be exploited

Acceptance Criteria

• Replace uses of Math.random()-based ID generation with crypto.randomBytes (Node) or other secure random APIs.

Details
The utils file comments indicate "Insecure random ID generation". Using non-crypto random for IDs is unsafe for security-sensitive contexts.