chore(io): remove shellexpand and use std::env::home_dir

[Xuanwo]

This PR will replace #5985 since we don't need a new dep

Summary

• remove shellexpand from workspace and lance-io dependencies
• replace tilde expansion in lance-io with std::env::home_dir-based logic
• keep support for ~ and ~/... paths (plus ~\\... on Windows)
• update lockfile to drop shellexpand

Validation

• cargo check -p lance-io
• cargo test -p lance-io test_tilde_expansion -- --nocapture

[github-actions]

PR Review

P1: std::env::home_dir() is deprecated

The new expand_tilde_path function uses std::env::home_dir(), which has been deprecated since Rust 1.29.0. The deprecation reason from the Rust docs:

This function's behavior is unexpected and probably not what you want. Consider using a crate from crates.io instead.

On Windows, it returns the value of the HOME environment variable, which can lead to inconsistent behavior compared to what users expect.

Recommendation: Since dirs (version 6.0.0) is already a transitive dependency in the workspace (used by hf-hub and other crates), consider using dirs::home_dir() instead. This would:

1. Avoid the deprecation warning
2. Provide more reliable cross-platform behavior
3. Not add any new dependencies

Example fix:

fn expand_tilde_path(path: &str) -> Option<std::path::PathBuf> {
    let home_dir = dirs::home_dir()?;
    // ... rest unchanged
}

This would require adding dirs to lance-io/Cargo.toml, but the crate is already in your dependency tree.

[codecov]

Codecov Report

❌ Patch coverage is 76.92308% with 3 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
rust/lance-io/src/object_store.rs	76.92%	1 Missing and 2 partials ⚠️

📢 Thoughts on this report? Let us know!

[westonpace]

Thanks for figuring this out!