Fix sample-dir path resolution for deployed layout

app.py

@@ -15,8 +15,19 @@ from lumen_rag.eval.harness import load_cases
 from lumen_rag.ingestion.loaders import _LOADERS, load_file
 from lumen_rag.retrieval import Retriever
 
-_SAMPLE_DIR = Path(__file__).resolve().parent.parent.parent / "data" / "docs"
-_EVAL_PATH = Path(__file__).resolve().parent.parent.parent / "data" / "eval.jsonl"
+def _find_repo_root() -> Path:
+    # Locally this file lives at deploy/hf-space/gradio_app.py (repo root 3 up);
+    # on the deployed Space it's copied to app.py at the repo root (0 up).
+    here = Path(__file__).resolve().parent
+    for candidate in (here, here.parent.parent.parent):
+        if (candidate / "data" / "docs").is_dir():
+            return candidate
+    return here
+
+
+_REPO_ROOT = _find_repo_root()
+_SAMPLE_DIR = _REPO_ROOT / "data" / "docs"
+_EVAL_PATH = _REPO_ROOT / "data" / "eval.jsonl"
 
 engine = RagEngine()