Fix verbatim prefix handling in junction creation

[DK26]

Fix verbatim prefix handling in junction creation

Summary

This PR fixes #30 where junction::create() silently fails when called with paths containing the Windows verbatim prefix (\\?\).

Problem

When paths from std::fs::canonicalize() are passed to junction::create(), the function returns Ok(()) but creates a broken junction that cannot be accessed. This is because:

1. get_full_path() returns the path with the verbatim prefix intact
2. create() then prepends the NT prefix \??\ unconditionally
3. The resulting reparse point data contains an invalid double prefix: \??\\\?\C:\...

Solution

Strip the Win32 verbatim prefix (\\?\) from the target path before constructing the reparse point data. This is done in create() right after calling get_full_path(), which is the correct location since:

• The Win32-to-NT path conversion is a concern of junction creation, not path normalization
• It matches the existing pattern in get_target() which strips the \??\ prefix when reading
• It uses strip_prefix().unwrap_or() so paths without the prefix are unchanged

Testing

• Added regression test create_with_verbatim_prefix_paths that uses fs::canonicalize() to obtain verbatim paths
• All existing tests continue to pass
• Manually verified all CI checks pass locally

[tesuji]

I'm sorry for not responding sooner.

LGTM with one nit.

[tesuji]

lgtm. Ty.

I misunderstood between \\.\ and \??\.