refactor(logger): refactor logger core architecture

[selcukcukur]

Overview

This PR performs a full architectural refinement of the logging core, focusing on :

• Simplifying the logger pipeline
• Removing unnecessary abstraction layers
• Preparing the system for async + thread-safe execution
• Improving memory safety and ownership clarity
• Aligning all components to a consistent production-ready design

This is not a feature change — it is a core internal restructuring for scalability and correctness.

Goals

• Make logger architecture explicit and predictable
• Remove hidden abstraction complexity
• Prepare system for async runtime compatibility
• Improve Rust ownership clarity (no implicit sharing assumptions)
• Ensure pipeline components are composable and isolated

Checklist

• Code follows existing architecture style
• No unnecessary abstraction introduced
• Handlers remain isolated
• Ordering behavior preserved
• Memory safety preserved
• Tests updated (if applicable)