Clean up Headless Mode Invocation and Implement Verbosity Levels

[LyalinDotCom]

What would you like to be added?

Objective

Ensure headless (non-interactive) invocation is strictly clean and produces only the intended output. This is a critical requirement for the 1.0 release to guarantee the CLI functions reliably for scripting, pipelines, and automation.

The Problem

Non-interactive mode currently leaks distracting initialization messages (such as "loading off" or "loading extensions") into the standard output stream. This pollution breaks scripts and utilities that rely on strict output formatting, such as parsing structured JSON payloads.

Why is this needed?

1. Strict Output Purity: Headless invocation must guarantee that standard output (stdout) contains only the requested data or response.
2. Degrees of Verbosity: Define and implement clear verbosity levels, offering users a choice between a completely clean output mode and a highly verbose mode for debugging.
3. Stream Separation: Ensure all initialization, loading, and diagnostic logs are properly routed to standard error (stderr) or suppressed entirely when operating in clean mode.

Additional context

No response