fix(annotator): autosave dir probe crashed on shallow paths (HF Space /app)

parents[2] raises IndexError when app.py sits near the filesystem root —
guard it. deploy_space.py now re-splits the subtree on every run and uses
get_token() (HfFolder was removed from huggingface_hub).

app.py

@@ -410,20 +410,21 @@ _LABEL_DISPLAY_DPI = 100  # the Review tab canvas coordinate space
 # annotation change is checkpointed to disk so a browser refresh/crash loses
 # nothing. Files go to a staging dir, NOT the canonical labels dir — the
 # canonical ground truth is only ever written via merge_labels.py.
-_REPO_WORKING_SET = Path(__file__).resolve().parents[2] / "data" / "working_set"
-
-
 def _resolve_autosave_dir():
     env = os.environ.get("FACADE_AUTOSAVE_DIR")
     if env:
         p = Path(env)
         p.mkdir(parents=True, exist_ok=True)
         return p
-    if _REPO_WORKING_SET.is_dir():
-        p = _REPO_WORKING_SET / "autosave"
+    try:
+        working_set = Path(__file__).resolve().parents[2] / "data" / "working_set"
+    except IndexError:  # app sits near filesystem root (HF Space: /app/app.py)
+        return None
+    if working_set.is_dir():
+        p = working_set / "autosave"
         p.mkdir(parents=True, exist_ok=True)
         return p
-    return None  # HF Space / standalone — autosave off
+    return None  # standalone checkout — autosave off
 
 
 _AUTOSAVE_DIR = _resolve_autosave_dir()