fix(docs): Resolve merge conflicts in README files

- Merge conflicting sections in README.md and README_EN.md
- Consolidate Supabase configuration instructions
- Remove duplicate and conflicting text blocks
- Improve clarity and consistency of documentation
- Ensure both English and Chinese README files have matching content structure

README.md

@@ -301,22 +301,12 @@ VITE_OPENAI_API_KEY=your_openai_key
 ```
 
 #### Supabase 配置（可选）
-<<<<<<< HEAD
 
 如需云端数据同步：
 1. 访问 [Supabase](https://supabase.com/) 创建项目
 2. 获取 URL 和匿名密钥
 3. 在 Supabase SQL 编辑器执行 `supabase/migrations/full_schema.sql`
 4. 在 `.env` 中配置相关参数
-=======
-1. 访问 [Supabase](https://supabase.com/) 创建新项目
-2. 在项目设置中获取 URL 和匿名密钥
-3. 运行数据库迁移脚本：
-   ```bash
-   # 在 Supabase SQL 编辑器中执行
-   cat supabase/migrations/full_schema.sql
-   ```
->>>>>>> 8e309314665ba010993d9164489b1e22c1c40cf8
 
 ## ✨ 核心功能
 

README_EN.md

@@ -302,7 +302,6 @@ VITE_OPENAI_API_KEY=your_openai_key
 ```
 
 #### Supabase Configuration (Optional)
-<<<<<<< HEAD
 
 For cloud data sync:
 1. Visit [Supabase](https://supabase.com/) to create a project
@@ -310,17 +309,6 @@ For cloud data sync:
 3. Execute `supabase/migrations/full_schema.sql` in Supabase SQL Editor
 4. Configure in `.env`
 
-> 💡 Without Supabase, system uses local database or demo mode
-=======
-1. Visit [Supabase](https://supabase.com/) to create a new project
-2. Get the URL and anonymous key from project settings
-3. Run database migration scripts:
-   ```bash
-   # Execute in Supabase SQL Editor
-   cat supabase/migrations/full_schema.sql
-   ```
->>>>>>> 8e309314665ba010993d9164489b1e22c1c40cf8
-
 ## ✨ Core Features
 
 <details>