julia

095e9b8e - path: overhaul `expanduser` and `contractuser` for cross-platform support

path: overhaul `expanduser` and `contractuser` for cross-platform support Rewrite `expanduser` to expand `~` to `homedir()` on all platforms. On Unix, `~username` is expanded via `homedir(username)`; on Windows, `~username` is left unexpanded since there is no reliable way to look up another user's home directory. Username validation rejects characters not found in valid usernames on any platform. The original separator after `~` or `~username` is preserved verbatim. Rewrite `contractuser` on both platforms to walk path prefixes using separator scanning and `samefile`-based inode comparison. When a prefix matches a home directory, the prefix is replaced with `~` (or `~username` on Unix) and the rest of the original path string is preserved verbatim. This handles symlinks and mixed separators transparently, and ensures `contractuser(expanduser(p)) == p`. On Unix, directory owners are checked to support `~username` contraction. Home directory stat results are cached to avoid redundant syscalls. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>