Update Dockerfile

Dockerfile

@@ -1,3 +1,4 @@
+# Force rebuild
 # 阶段 1：克隆项目并构建前端
 FROM node:lts-slim AS frontend-builder
 
@@ -48,6 +49,9 @@ COPY --from=frontend-builder /app/requirements.txt .
 # 安装 Python 依赖
 RUN pip install --no-cache-dir -r requirements.txt
 
+# 显式安装 gunicorn
+RUN pip install --no-cache-dir gunicorn==22.0.0
+
 # 安装 huggingface_hub
 RUN pip install --no-cache-dir huggingface_hub