chore: 初始化项目结构并添加基础配置文件

添加后端API和前端项目的初始目录结构，包括应用层模块、工具模块和模型定义
配置前后端的.dockerignore文件以排除开发环境文件
添加前端样式文件，包括字体、Tailwind CSS和主题配置
初始化Python虚拟环境中的类型标记文件

后端-孕期报告解读-api/app/config.py

@@ -0,0 +1,39 @@
+from pydantic_settings import BaseSettings
+
+
+class Settings(BaseSettings):
+    # MongoDB
+    mongodb_url: str = "mongodb://localhost:27017"
+    mongodb_db_name: str = "pregnancy_report"
+
+    # JWT
+    jwt_secret_key: str = "change-this-secret-key"
+    jwt_algorithm: str = "HS256"
+    jwt_expire_minutes: int = 10080  # 7 days
+
+    # WeChat
+    wechat_app_id: str = ""
+    wechat_app_secret: str = ""
+
+    # AI API (OpenAI 兼容接口，如硅基流动)
+    ai_api_key: str = ""
+    ai_base_url: str = "https://api.siliconflow.cn/v1"
+    ai_vision_model: str = "Qwen/Qwen2.5-VL-72B-Instruct"
+    ai_text_model: str = "Qwen/Qwen2.5-72B-Instruct"  # 使用更快的72B模型
+
+    # Upload
+    upload_dir: str = "./uploads"
+    max_file_size: int = 10 * 1024 * 1024  # 10MB
+
+    # CORS
+    cors_origins: str = "*"  # 多个域名用逗号分隔，如 https://a.com,https://b.com
+
+    # Server
+    host: str = "0.0.0.0"
+    port: int = 8000
+    debug: bool = True
+
+    model_config = {"env_file": ".env", "env_file_encoding": "utf-8"}
+
+
+settings = Settings()