Using `Path::display` to construct a new `Path`

What it does

Detect when FS operations are being done using a fresly-constructed String from Paths. Instead, devs should be using Path::join to avoid an unnecessarily lossy transformation.

Advantage

Code is more robust to paths that are not representable by UTF-8 strings.

Drawbacks

The detection logic might be too difficult to accomplish for the general case.

The correct code might be difficult to automatically suggest.

Example

    let p = "foo";
    let bar = "bar";
    let _ = fs::create_file(format!("{}/bar", p.display()));
    let _ = fs::create_file(format!("{}/{}", p.dispaly(), bar.display()));

Could be written as:

    let _ = fs::create_file(p.join("bar"));
    let _ = fs::create_file(p..join(bar));

Comparison with existing lints

No response

Additional Context

No response

No files, tests, or entry points are named in the issue. Start from the Rust examples and define the detection boundary and expected suggestion for Path::display cases; done means the intended cases and limitations are documented well enough to assess an implementation.