Clarify --ckpt help: retriever weights only, not full DSv4 model

demo.py

@@ -54,7 +54,8 @@ def make_mock_compressed_k(
 
 def main():
     ap = argparse.ArgumentParser(description="FlashMemory DS-V4 Retriever demo")
-    ap.add_argument("--ckpt", required=True, help="path to joint checkpoint (.pt)")
+    ap.add_argument("--ckpt", required=True,
+                help="path to retriever checkpoint (flashmemory_ds_v4.safetensors from HuggingFace, NOT a full DSv4 model)")
     ap.add_argument("--device", default="cpu", help="cpu or cuda (default: cpu)")
     ap.add_argument("--batch", type=int, default=2, help="number of decode tokens")
     ap.add_argument("--n-chunks", type=int, default=64, help="number of compressed-K chunks")

toy_flashmemory_inference.py

@@ -214,7 +214,8 @@ def main():
     ap = argparse.ArgumentParser(
         description="Toy DeepSeek-V4-FlashMemory sparse-decode loop driven by the FlashMemory Retriever"
     )
-    ap.add_argument("--ckpt", required=True, help="path to the FlashMemory DS-V4 joint checkpoint (.pt)")
+    ap.add_argument("--ckpt", required=True,
+                    help="path to the retriever checkpoint (flashmemory_ds_v4.safetensors from HuggingFace, NOT a full DSv4 model)")
     ap.add_argument("--device", default="cpu", help="cpu or cuda (default: cpu)")
     ap.add_argument("--batch", type=int, default=1, help="number of parallel decode sequences")
     ap.add_argument("--n-chunks", type=int, default=256, help="number of CSA memory chunks (the long history)")