The early return optimization in #2155 broke the contract that LavaFormat*
functions always return an error. When log level was disabled and no original
error was passed, it returned nil instead of an error.

This caused issues like:
return nil, utils.LavaFormatTrace("error message")
to return (nil, nil) instead of (nil, error), leading to nil pointer panics
in code that relied on the error return.

Changes:

• utils/lavalog.go: Return fmt.Errorf based on description when log level
• disabled and no original error
• protocol/parser/parser.go: Add defensive nil checks as safety net

Description

Closes: #XXXX

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