Initial commit: TradeMate 外贸小助手 MVP

项目结构:
- backend/     Python FastAPI 后端
- uni-app/     uni-app跨端前端
- docs/        设计文档
- docker-compose.yml  Docker编排
- nginx/scripts/systemd 运维配置

已完成功能:
- 用户认证 (JWT)
- 智能翻译 + 回复建议
- 营销素材生成
- 客户管理 + 沉默检测
- 报价单管理
- 产品库管理
- 汇率换算
- 推送通知 (uni-push)
- WhatsApp Webhook框架
- Celery定时任务

backend/app/ai/base.py

@@ -0,0 +1,45 @@
+from abc import ABC, abstractmethod
+from typing import Dict, Any, Optional
+
+
+class AIProvider(ABC):
+    @abstractmethod
+    async def translate(
+        self, text: str, source_lang: Optional[str], target_lang: str,
+        context: Optional[str] = None,
+    ) -> Dict[str, Any]:
+        pass
+
+    @abstractmethod
+    async def reply(
+        self, inquiry: str, context: Optional[Dict[str, Any]] = None,
+        tone: str = "professional",
+    ) -> Dict[str, Any]:
+        pass
+
+    @abstractmethod
+    async def generate_marketing(
+        self, product_info: Dict[str, Any], target: str,
+        style: str = "professional", language: str = "en",
+    ) -> Dict[str, Any]:
+        pass
+
+    @abstractmethod
+    async def extract_info(
+        self, text: str, schema: Dict[str, Any],
+    ) -> Dict[str, Any]:
+        pass
+
+    @property
+    @abstractmethod
+    def name(self) -> str:
+        pass
+
+    @property
+    @abstractmethod
+    def cost_per_1k_tokens(self) -> float:
+        pass
+
+    @property
+    def supports_streaming(self) -> bool:
+        return False