Update class_file_manager.py

Enhanced the JSON validation error dialogs for Classification file managers by appending modality-specific Hugging Face download links to guide users to the correct dataset formats.

Author: woshimajintao

annotation_tool/controllers/classification/class_file_manager.py

@@ -24,11 +24,19 @@ def load_project(self, data, file_path):
              # Truncate extremely long error messages for display
             if len(err) > 1000:
                 err = err[:1000] + "\n... (truncated)"
+
+            error_text = (
+                "The imported JSON contains critical errors and cannot be loaded.\n\n"
+                f"{err}\n\n"
+                "--------------------------------------------------\n"
+                "💡 Please download the correct Classification JSON format from:\n"
+                "https://huggingface.co/datasets/OpenSportsLab/soccernetpro-classification-vars"
+            )
 
             QMessageBox.critical(
                 self.main, 
                 "Validation Error (Classification)", 
-                "The imported JSON contains critical errors and cannot be loaded.\n\n" + err
+                error_text
             )
             return False # [FIX] Return False to signal failure
 
@@ -241,4 +249,4 @@ def _clear_workspace(self, full_reset=False):
         self.ui.classification_ui.right_panel.manual_box.setEnabled(False)
         self.ui.classification_ui.center_panel.show_single_view(None)
         if full_reset: 
-            self.main.setup_dynamic_ui()
+            self.main.setup_dynamic_ui()