Recognize macOS extraction helper staging and verify release resources

docs/EXTRACTION-ISOLATION.md

@@ -215,3 +215,16 @@ Windows throughput, cold filesystem caches or steady-state search latency.
 No persistent parser/cache optimization is justified by this small observation.
 Raw ignored report: `.searchi/qa/document-throughput-013.json`, SHA-256
 `b86df0bf2ca0953317033b35b4642e6e0fadb93e50c499a7a28b1ae82512acd1`.
+
+## macOS staging preparation
+
+The helper staging tool now detects Darwin as macOS, recognizes native thin
+64-bit little-endian Mach-O executables for Intel/Apple Silicon, and preserves
+executable mode. Desktop release verification now covers macOS too. Header
+layout and constants follow Apple's [loader header](https://github.com/apple-oss-distributions/xnu/blob/main/EXTERNAL_HEADERS/mach-o/loader.h)
+and [CPU definitions](https://github.com/apple-oss-distributions/xnu/blob/main/osfmk/mach/machine.h).
+Six staging tests passed normally and under optimized Python, including mocked
+Darwin defaults and synthetic header rejection. The actual staged Windows
+helper still verifies. This is preparation only: native macOS build, loader
+closure, resource-limit behavior, signing and application execution remain open.
+Universal/fat extraction-helper binaries are not supported by this staging tool.