Expose LakeSoul Rust build version and git commit information

Motivation

When debugging production issues or validating compatibility, it is often useful to know exactly which LakeSoul Rust build is being used.

Currently, there is no public API to retrieve build information such as:

• LakeSoul version
• Git commit SHA
• Build timestamp (optional)

This makes it difficult to identify the exact binary version when users report issues.

Proposal

Expose a public version API in the Rust implementation, for example:

pub fn version() -> &'static str;

pub struct BuildInfo {
    pub version: &'static str,
    pub git_commit: &'static str,
    pub build_time: &'static str,
}

pub fn build_info() -> BuildInfo;