变更项目架构，提高扩展性

backend/core/config.py

@@ -0,0 +1,24 @@
+from pydantic_settings import BaseSettings, SettingsConfigDict
+
+class Settings(BaseSettings):
+    """
+    系统配置类
+    自动读取环境变量或 .env 文件
+    """
+    DB_USER: str
+    DB_PASS: str
+    DB_HOST: str
+    DB_PORT: str = "5432"
+    DB_NAME: str
+
+    DASHSCOPE_API_KEY: str
+    FIRECRAWL_API_KEY: str
+
+    # 配置：忽略多余的环境变量，指定编码
+    model_config = SettingsConfigDict(env_file=".env", extra="ignore", env_file_encoding='utf-8')
+
+    @property
+    def DATABASE_URL(self) -> str:
+        return f"postgresql+psycopg2://{self.DB_USER}:{self.DB_PASS}@{self.DB_HOST}:{self.DB_PORT}/{self.DB_NAME}"
+
+settings = Settings()