perf: RawBufferSource value_as_string

[SyMind]

This PR optimizes the RawBufferSource struct to avoid unnecessary string allocations by using self-referential structs and Cow<'this, str> instead of String. The change leverages the ouroboros crate to create self-referential structures that can borrow from their own data.

[Copilot]

Pull Request Overview

This PR optimizes the RawBufferSource struct to avoid unnecessary string allocations by using self-referential structs and Cow<'this, str> instead of String. The change leverages the ouroboros crate to create self-referential structures that can borrow from their own data.

• Replaced OnceLock<String> with OnceLock<Cow<'this, str>> to avoid string copying
• Converted RawBufferSource to a self-referential struct using the ouroboros crate
• Added custom implementations for Clone, PartialEq, and Eq traits

Reviewed Changes

Copilot reviewed 2 out of 3 changed files in this pull request and generated 2 comments.

File	Description
src/raw_source.rs	Converted RawBufferSource to self-referential struct and optimized string handling
Cargo.toml	Added ouroboros = "0.18.5" dependency for self-referential struct support

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[codspeed-hq]

CodSpeed Performance Report

Merging #167 will not alter performance

_{Comparing SyMind:refactor-raw-buffer-source (608e809) with main (79e2dfc)}

Summary

✅ 7 untouched