feat: upload huggingrun.log to dataset for debugging

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

entrypoint.py

@@ -263,8 +263,8 @@ def save_and_upload():
     ok = 0
     fail = 0
 
-    # Upload package list files
-    for pf, name in [(PKG_FILE, "user-packages.list"), (PIP_FILE, "pip-packages.txt")]:
+    # Upload package list files + log
+    for pf, name in [(PKG_FILE, "user-packages.list"), (PIP_FILE, "pip-packages.txt"), (LOGFILE, "huggingrun.log")]:
         if os.path.exists(pf):
             try:
                 api.upload_file(