feat: 添加大纲写作功能与服务器端改进

- 新增 OutlineWriterPanel 和 OutlineResultPanel 组件
- 重构服务器端数据库接口 (server/db.js)
- 添加 LLM 服务模块 (server/llm.js)
- 更新配置和设置面板
- 优化文档选择器和素材面板
- 更新部署文档和环境变量示例

.env.example

@@ -1,28 +1,39 @@
-# AI 写作工坊 - 模型服务商配置
-# 复制此文件为 .env 并填入您的 API Key
+# AI 写作工坊 - 服务端模型与数据库配置
+# 复制此文件为 .env 并填入服务端 API Key
+
+# ========== 服务端 API ==========
+API_PORT=3001
 
 # ========== DeepSeek (默认) ==========
-VITE_DEEPSEEK_API_URL=https://api.deepseek.com/chat/completions
-VITE_DEEPSEEK_API_KEY=your_deepseek_api_key_here
-VITE_DEEPSEEK_MODEL=deepseek-chat
+DEEPSEEK_API_URL=https://api.deepseek.com/chat/completions
+DEEPSEEK_API_KEY=your_deepseek_api_key_here
+DEEPSEEK_MODEL=deepseek-chat
 
 # ========== 千帆大模型 (百度文心一言) ==========
-# VITE_QIANFAN_API_URL=https://qianfan.baidubce.com/v2/chat/completions
-# VITE_QIANFAN_API_KEY=your_bearer_token_here
-# VITE_QIANFAN_APP_ID=your_app_id_here
-# VITE_QIANFAN_MODEL=ernie-4.0-8k
+# QIANFAN_API_URL=https://qianfan.baidubce.com/v2/chat/completions
+# QIANFAN_API_KEY=your_bearer_token_here
+# QIANFAN_APP_ID=your_app_id_here
+# QIANFAN_MODEL=ernie-4.0-8k
 
 # ========== OpenAI ==========
-# VITE_OPENAI_API_URL=https://api.openai.com/v1/chat/completions
-# VITE_OPENAI_API_KEY=your_openai_api_key_here
-# VITE_OPENAI_MODEL=gpt-4o
+# OPENAI_API_URL=https://api.openai.com/v1/chat/completions
+# OPENAI_API_KEY=your_openai_api_key_here
+# OPENAI_MODEL=gpt-4o
 
 # ========== Claude (Anthropic) ==========
-# VITE_CLAUDE_API_URL=https://api.anthropic.com/v1/messages
-# VITE_CLAUDE_API_KEY=your_claude_api_key_here
-# VITE_CLAUDE_MODEL=claude-3-5-sonnet
+# CLAUDE_API_URL=https://api.anthropic.com/v1/messages
+# CLAUDE_API_KEY=your_claude_api_key_here
+# CLAUDE_MODEL=claude-3-5-sonnet
 
 # ========== 自定义 API 中继 ==========
-# VITE_CUSTOM_API_URL=https://your-api-gateway.com/v1/chat/completions
-# VITE_CUSTOM_API_KEY=your_custom_api_key_here
+# CUSTOM_API_URL=https://your-api-gateway.com/v1/chat/completions
+# CUSTOM_API_KEY=your_custom_api_key_here
+# CUSTOM_MODEL=your_model_name
+
+# ========== 前端配置（仅展示，不含密钥） ==========
+VITE_API_BASE=http://localhost:3001/api
+# VITE_DEEPSEEK_MODEL=deepseek-chat
+# VITE_QIANFAN_MODEL=ernie-4.0-8k
+# VITE_OPENAI_MODEL=gpt-4o
+# VITE_CLAUDE_MODEL=claude-3-5-sonnet
 # VITE_CUSTOM_MODEL=your_model_name