Fix ref_dir UnboundLocalError in self-hosting bootstrapper page

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

sx/sxc/pages/helpers.py

@@ -233,13 +233,13 @@ def _bootstrapper_data(target: str) -> dict:
     if target not in ("javascript", "python", "self-hosting"):
         return {"bootstrapper-not-found": True}
 
-    if target == "self-hosting":
-        return _self_hosting_data(ref_dir)
-
     ref_dir = os.path.join(os.path.dirname(__file__), "..", "..", "shared", "sx", "ref")
     if not os.path.isdir(ref_dir):
         ref_dir = "/app/shared/sx/ref"
 
+    if target == "self-hosting":
+        return _self_hosting_data(ref_dir)
+
     if target == "javascript":
         # Read bootstrapper source
         bs_path = os.path.join(ref_dir, "bootstrap_js.py")