Fix: Monkey-patch aistudio_sdk.hub.download before importing PaddleNLP

- Set HUB_DISABLE_DOWNLOAD=1 environment variable
- Inject fake aistudio_sdk.hub.download into sys.modules
- Intercept calls to aistudio_sdk before PaddleNLP imports
- This prevents the 'cannot import name download' error

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

models/sentiment.py

@@ -95,9 +95,12 @@ class SentimentAnalyzer:
 
     def _load_paddlenlp_model(self, model_path: str):
         """使用 PaddleNLP 加载模型"""
+        # 先尝试禁用 aistudio_sdk，然后再导入 PaddleNLP
+        import os
+        os.environ['HUB_DISABLE_DOWNLOAD'] = '1'
+
         try:
             import paddle
-            from paddlenlp.transformers import BertModel, BertTokenizer
             from paddle.nn import Layer
             from paddle.nn import Linear, Dropout
 
@@ -131,7 +134,23 @@ class SentimentAnalyzer:
                     with open(tokenizer_config_path, 'r') as f:
                         tokenizer_config = json.load(f)
 
-                # 手动构建 tokenizer（使用底层 API）
+                # 延迟导入 - 只在真正需要时才导入
+                # 使用 exec 来避免模块级导入
+                import sys
+                import types
+
+                # 创建一个假的模块来拦截 aistudio_sdk 调用
+                class FakeAistudioHub:
+                    @staticmethod
+                    def download(*args, **kwargs):
+                        return None
+
+                # 注入假模块
+                sys.modules['aistudio_sdk'] = types.ModuleType('aistudio_sdk', ())
+                sys.modules['aistudio_sdk.hub'] = types.ModuleType('aistudio_sdk.hub', ())
+                sys.modules['aistudio_sdk.hub'].download = FakeAistudioHub.download
+
+                # 现在可以安全地导入 BertTokenizer
                 from paddlenlp.transformers import BertTokenizer as BT
                 self.tokenizer = BT(
                     vocab,
@@ -147,8 +166,8 @@ class SentimentAnalyzer:
                 class BertClassificationModel(Layer):
                     def __init__(self, config_dict, num_labels=3):
                         super().__init__()
-                        # 使用底层 BertModel，避免触发 aistudio_sdk
-                        from paddlenlp.transformers import BertConfig
+                        # 延迟导入 BertModel
+                        from paddlenlp.transformers import BertConfig, BertModel
                         bert_config = BertConfig(
                             vocab_size=config_dict.get('vocab_size', 21128),
                             hidden_size=config_dict.get('hidden_size', 768),