add workaround in ensure_weights to deal with persmission error

app.py

@@ -12,6 +12,7 @@ import gc
 import io
 from contextlib import redirect_stdout, redirect_stderr
 import sys, llama_cpp
+import shutil
 
 # ----------------------------------------
 # Model configurations: per-size prefixes and repos
@@ -53,17 +54,25 @@ model_cache = {
 }
 
 # Helper to download & symlink weights
+def ensure_weights(cfg, model_file, clip_file):
+    # download into HF cache (now in /tmp/.cache)
+    path = hf_hub_download(repo_id=cfg['model_repo'], filename=model_file)
 
-def ensure_weights(size, model_file, clip_file):
-    cfg = MODELS[size]
-    if not os.path.exists(model_file):
-        logging.info(f"Downloading model file {model_file} from {cfg['model_repo']}...")
-        path = hf_hub_download(repo_id=cfg['model_repo'], filename=model_file)
+    # try to link into your working dir, else copy
+    try:
         os.symlink(path, model_file)
-    if not os.path.exists(clip_file):
-        logging.info(f"Downloading CLIP file {clip_file} from {cfg['clip_repo']}...")
-        path = hf_hub_download(repo_id=cfg['clip_repo'], filename=clip_file)
-        os.symlink(path, clip_file)
+    except (PermissionError, OSError):
+        print(f"⚠️ symlink failed, copying {path} → {model_file}")
+        shutil.copy2(path, model_file)
+
+    # repeat for clip_file…
+    clip_path = hf_hub_download(repo_id=cfg['clip_repo'], filename=clip_file)
+    try:
+        os.symlink(clip_path, clip_file)
+    except (PermissionError, OSError):
+        print(f"⚠️ symlink failed, copying {clip_path} → {clip_file}")
+        shutil.copy2(clip_path, clip_file)
+
     return model_file, clip_file
 
 # Custom chat handler