chore: import upstream snapshot with attribution

crates/jcode-core/src/fs.rs

@@ -0,0 +1,33 @@
+use std::path::Path;
+
+/// Set file permissions to owner-only read/write (0o600).
+/// No-op on Windows.
+pub fn set_permissions_owner_only(path: &Path) -> std::io::Result<()> {
+    #[cfg(unix)]
+    {
+        use std::os::unix::fs::PermissionsExt;
+        let perms = std::fs::Permissions::from_mode(0o600);
+        std::fs::set_permissions(path, perms)
+    }
+    #[cfg(windows)]
+    {
+        let _ = path;
+        Ok(())
+    }
+}
+
+/// Set directory permissions to owner-only read/write/execute (0o700).
+/// No-op on Windows.
+pub fn set_directory_permissions_owner_only(path: &Path) -> std::io::Result<()> {
+    #[cfg(unix)]
+    {
+        use std::os::unix::fs::PermissionsExt;
+        let perms = std::fs::Permissions::from_mode(0o700);
+        std::fs::set_permissions(path, perms)
+    }
+    #[cfg(windows)]
+    {
+        let _ = path;
+        Ok(())
+    }
+}