chore: imporve error logs in server/cluster/cluser.go

[SuminSSon]

Summary

There are numerous instances in the source code where errors are returned without context using fmt.Errorf(). This makes debugging more challenging.

Motivation

Providing context in error messages helps developers understand where and why an error occurred, making it easier to debug issues.

Proposal

Identify locations in the code where errors are returned without wrapping them and add appropriate context.

Example:

// Old code
err := c.cache.GetItem()
if err != nil {
    return err
}

// New code
err := c.cache.GetItem()
if err != nil {
    return fmt.Errorf("error getting item from the cache: %w", err)
}