docs: add bilingual CONTRIBUTING.md (Chinese + English)

- Added a CONTRIBUTING.md with both Chinese and English versions.
- Provides clear instructions for contributing based on the dev branch.

+# Contribution Guide
+
+Thank you for contributing to this project!
+To maintain code quality and a clean version history, please follow the steps below when submitting your changes.
+
+# 🪄 How to Submit a Pull Request (PR)
+
+## 1️⃣ Fork the Repository
+
+Fork this repository to your GitHub account.
+
+## 2️⃣ Clone to Your Local Machine
+
+```bash
+git clone https://github.com/<your-username>/<repository-name>.git
+cd <repository-name>
+```
+
+## 3️⃣ Switch to the `dev` Branch (Make Sure You Base Your Work on the Latest Code)
+
+```bash
+git checkout dev
+```
+
+> ⚠️ Always create your feature branch from **`dev`**, not `main`.
+
+## 4️⃣ Create a Feature Branch
+
+```bash
+git checkout -b feature/your-feature-name
+```
+
+> Recommended branch naming conventions: `feature/xxx` or `fix/xxx` for easy identification of features or bug fixes.
+
+## 5️⃣ Develop and Test
+
+* Make your code changes while keeping the project’s coding style consistent.
+* Ensure that new features or fixes pass all tests.
+
+## 6️⃣ Commit Your Changes
+
+```bash
+git add .
+git commit -m "type: short description"
+```
+
+> It is recommended to follow [Conventional Commits](https://www.conventionalcommits.org/), keeping the commit history clear.
+
+## 7️⃣ Push to Your Remote Repository
+
+```bash
+git push origin feature/your-feature-name
+```
+
+## 8️⃣ Open a Pull Request
+
+1. Click **New Pull Request** on GitHub.
+2. **The target branch must be this repository’s `dev` branch**.
+3. Fill in the PR description:
+
+   * Explain the main changes.
+   * Link any related issues if applicable.
+
+> ⚠️ Do **not** target the `main` branch with your PR to avoid affecting the stable mainline.

+# 贡献指南
+
+感谢你愿意为本项目做出贡献！
+为了保持代码质量和版本管理的清晰，请按照以下步骤提交你的修改。
+
+# 🪄 提交 Pull Request（PR）步骤
+
+## 1️⃣ Fork 仓库
+
+将本仓库 Fork 到你的 GitHub 账户。
+
+## 2️⃣ 克隆到本地
+
+```bash
+git clone https://github.com/<你的用户名>/<仓库名>.git
+cd <仓库名>
+```
+
+## 3️⃣ 切换到 `dev` 分支（确保基于最新代码开发）
+
+```bash
+git checkout dev
+```
+
+> ⚠️ 请务必从 **`dev` 分支** 创建你的功能分支，而不是从 `main`。
+
+## 4️⃣ 创建功能分支
+
+```bash
+git checkout -b feature/你的功能名
+```
+
+> 建议分支命名规范：`feature/xxx` 或 `fix/xxx`，便于识别功能或修复类型。
+
+## 5️⃣ 开发与测试
+
+* 进行代码修改，保持项目代码风格一致。
+* 确保新增功能或修复通过测试。
+
+## 6️⃣ 提交修改
+
+```bash
+git add .
+git commit -m "类型: 简短描述"
+```
+
+> 推荐遵循 [Conventional Commits](https://www.conventionalcommits.org/zh-hans/)，保持提交记录清晰。
+
+## 7️⃣ 推送到远程仓库
+
+```bash
+git push origin feature/你的功能名
+```
+
+## 8️⃣ 发起 Pull Request
+
+1. 在 GitHub 上点击 **New Pull Request**。
+2. **目标分支必须是本仓库的 `dev` 分支**。
+3. 填写 PR 描述：
+
+   * 说明主要改动内容
+   * 如有相关 issue，请在 PR 中关联
+
+> ⚠️ PR **绝对不要指向 `main` 分支**，避免影响主线稳定性。