Refactor project structure by removing Docker support and updating environment configuration

- Deleted docker-compose.yml, backend Dockerfile, frontend Dockerfile, and nginx configuration to streamline project setup.
- Updated .env.example to reorganize LLM and ZEP API configurations for clarity and ease of use.
- Enhanced README.md to reflect changes in project structure and provide clearer setup instructions.

.env.example

@@ -1,11 +1,13 @@
-# ===== ZEP记忆图谱配置 =====
-ZEP_API_KEY=your_zep_api_key_here
-
-# ===== 通用 LLM 配置 =====
+# LLM API配置（支持 OpenAI SDK 格式的任意 LLM）
+# 推荐使用阿里百炼平台Qwen-plus模型：https://bailian.console.aliyun.com/
 LLM_API_KEY=your_api_key_here
 LLM_BASE_URL=https://dashscope.aliyuncs.com/compatible-mode/v1
 LLM_MODEL_NAME=qwen-plus
 
+# ===== ZEP记忆图谱配置 =====
+# 每月免费额度即可支撑使用：https://app.getzep.com/
+ZEP_API_KEY=your_zep_api_key_here
+
 # ===== 加速 LLM 配置（可选）=====
 LLM_BOOST_API_KEY=your_boost_api_key_here
 LLM_BOOST_BASE_URL=https://another-api-provider.com/v1