chore: import upstream snapshot with attribution

Sources/ContainerizationOS/FilePathOps.swift

@@ -0,0 +1,38 @@
+//===----------------------------------------------------------------------===//
+// Copyright © 2026 Apple Inc. and the Containerization project authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//   https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//===----------------------------------------------------------------------===//
+
+import Foundation
+import SystemPackage
+
+/// Static utility functions for path operations.
+///
+/// The type is never instantiated; it exists solely as a namespace.
+public enum FilePathOps {
+    /// Returns an absolute version of `path`.
+    ///
+    /// This is a purely lexical operation: it does not resolve symlinks,
+    /// perform tilde expansion, and does not access the file system. If `path`
+    /// is already absolute, this returns `path` unchanged.
+    public static func absolutePath(_ path: FilePath) -> FilePath {
+        guard !path.isAbsolute else {
+            return path
+        }
+
+        return FilePath(FileManager.default.currentDirectoryPath)
+            .appending(path.components)
+            .lexicallyNormalized()
+    }
+}