Add debug output to HuggingFace API validation

Adds comprehensive debugging to help troubleshoot HuggingFace token validation issues:
- Shows API response status code and error messages
- Displays user info returned by API
- Compares expected vs actual usernames
- Captures and displays any exceptions

This will help diagnose whether token issues are API-related, token-related, or username mismatches.

🤖 Generated with [Claude Code](https://claude.ai/code)

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

Author: jeremymanning

clustrix/notebook_magic.py

@@ -2097,10 +2097,35 @@ def _test_huggingface_connectivity(self, config):
                 "https://huggingface.co/api/whoami", headers=headers, timeout=10
             )
 
+            # Debug: Print response details for troubleshooting
+            if hasattr(self, "status_output"):
+                with self.status_output:
+                    print(
+                        f"🔍 Debug: HuggingFace API response status: {response.status_code}"
+                    )
+                    if response.status_code != 200:
+                        print(f"🔍 Debug: Response text: {response.text[:200]}...")
+
             if response.status_code == 200:
                 user_info = response.json()
+
+                # Debug: Print user info for troubleshooting
+                if hasattr(self, "status_output"):
+                    with self.status_output:
+                        print(f"🔍 Debug: User info keys: {list(user_info.keys())}")
+                        print(
+                            f"🔍 Debug: User name from API: '{user_info.get('name', 'NOT_FOUND')}'"
+                        )
+                        if hf_username:
+                            print(f"🔍 Debug: Expected username: '{hf_username}'")
+
                 # Verify username if provided
                 if hf_username and user_info.get("name") != hf_username:
+                    if hasattr(self, "status_output"):
+                        with self.status_output:
+                            print(
+                                f"🔍 Debug: Username mismatch - API: '{user_info.get('name')}', Expected: '{hf_username}'"
+                            )
                     return False
                 return True
 
@@ -2109,7 +2134,11 @@ def _test_huggingface_connectivity(self, config):
         except ImportError:
             print("ℹ️  requests library not available for HuggingFace testing")
             return False
-        except Exception:
+        except Exception as e:
+            # Debug: Print exception details
+            if hasattr(self, "status_output"):
+                with self.status_output:
+                    print(f"🔍 Debug: Exception during HuggingFace test: {str(e)}")
             return False
 
     def _on_test_config(self, button):