第一步

backend/app/core/config.py

@@ -0,0 +1,66 @@
+"""全局配置：pydantic-settings，全部来自环境变量 / .env。
+
+规则（docs/technical-review.md §1.3）：
+- 密钥不得硬编码；SECRET_KEY 缺失或仍为模板值时，生产环境拒绝启动。
+- DATABASE_URL 可切换 PostgreSQL（扩展接口 1）。
+"""
+
+from functools import lru_cache
+from pathlib import Path
+
+from pydantic import Field
+from pydantic_settings import BaseSettings, SettingsConfigDict
+
+_TEMPLATE_MARKERS = ("change-me",)
+
+
+class Settings(BaseSettings):
+    model_config = SettingsConfigDict(env_file=".env", env_file_encoding="utf-8", extra="ignore")
+
+    # --- 基础 ---
+    environment: str = "local"  # local / production
+    secret_key: str = Field(min_length=16)
+
+    # --- 数据库 ---
+    database_url: str = "sqlite:///./data/app.db"
+
+    # --- 文件存储 ---
+    storage_root: str = "./data"
+
+    # --- 套餐 ---
+    default_storage_quota: int = 104_857_600   # 100 MB
+    default_max_file_size: int = 20_971_520    # 20 MB
+
+    # --- 限流 ---
+    rate_limit_per_token_per_min: int = 60
+    rate_limit_per_ip_per_min: int = 30
+
+    # --- CORS ---
+    frontend_origin: str = "http://localhost:5173"
+
+    @property
+    def is_production(self) -> bool:
+        return self.environment == "production"
+
+    @property
+    def storage_root_path(self) -> Path:
+        return Path(self.storage_root).resolve()
+
+    def validate_secrets(self) -> None:
+        """生产环境禁止携带模板密钥启动。"""
+        if not self.is_production:
+            return
+        for field_name in ("secret_key",):
+            value = getattr(self, field_name).lower()
+            if any(marker in value for marker in _TEMPLATE_MARKERS):
+                raise RuntimeError(
+                    f"配置错误：{field_name} 仍为模板值，生产环境禁止启动。"
+                    "请运行: python -c \"import secrets; print(secrets.token_urlsafe(48))\""
+                )
+
+
+@lru_cache
+def get_settings() -> Settings:
+    s = Settings()  # type: ignore[call-arg]
+    s.validate_secrets()
+    return s