chore: import upstream snapshot with attribution

Sources/ContainerVersion/Bundle+AppBundle.swift

@@ -0,0 +1,46 @@
+//===----------------------------------------------------------------------===//
+// Copyright © 2025-2026 Apple Inc. and the container 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 Darwin
+import Foundation
+import SystemPackage
+
+extension Bundle {
+    /// Retrieves the application bundle for a path that refers to a macOS executable.
+    ///
+    /// Resolves symlinks in `executablePath`, then walks up the standard macOS bundle layout
+    /// (`MacOS/` → `Contents/` → `Foo.app/`) and verifies the `.app` extension.
+    ///
+    /// - Parameter executablePath: The path to a macOS executable inside a bundle.
+    /// - Returns: The ``Bundle`` at the resolved `.app` directory, or `nil` if the executable
+    ///   is not inside a valid macOS application bundle.
+    public static func appBundle(executablePath: FilePath) -> Bundle? {
+        let resolvedPath =
+            executablePath.withPlatformString { cPath in
+                Darwin.realpath(cPath, nil).map { ptr -> FilePath in
+                    defer { free(ptr) }
+                    return FilePath(platformString: ptr)
+                }
+            } ?? executablePath
+        let bundlePath =
+            resolvedPath
+            .removingLastComponent()  // MacOS/
+            .removingLastComponent()  // Contents/
+            .removingLastComponent()  // Foo.app/
+        guard bundlePath.lastComponent?.extension == "app" else { return nil }
+        return Bundle(url: URL(fileURLWithPath: bundlePath.string))
+    }
+}