chore(go): scaffold module and add failing link tests

README.md

@@ -111,6 +111,20 @@ Run against a future Go binary (example path):
 
 The command under test is controlled with the `HOMESICK_CMD` environment variable. By running the same suite for both implementations, you can verify parity at the behavior level.
 
+## Go Scaffold
+
+Initial Go scaffolding now lives under [cmd/homesick](cmd/homesick) and [internal/homesick](internal/homesick).
+
+Build the Go binary:
+
+    just go-build
+
+Run behavior validation against the Go binary:
+
+    HOMESICK_CMD="/workspace/dist/homesick-go" just behavior-go
+
+At this stage, the Go implementation includes a subset of commands (`clone`, `list`, `show_path`, `status`, `diff`, `version`) and intentionally reports clear errors for commands that are not ported yet.
+
 ## .homesick_subdir
 
 `homesick link` basically makes symlink to only first depth in `castle/home`. If you want to link nested files/directories, please use .homesick_subdir.