Adopt per-module folder structure for design documents

Co-authored-by: bearguo <20483603+bearguo@users.noreply.github.com>

Author: Copilot

.github/copilot-instructions.md

@@ -23,22 +23,22 @@ templates/tech-design-template.md
 
 ### Step 3: Save the Document
 
-Save the new document to the `docs/` directory using the naming convention:
+Create a dedicated folder for the module inside `docs/` and save the document as `tech-design.md` within it:
 ```
-docs/<feature-name>-tech-design.md
+docs/<feature-name>/tech-design.md
 ```
 
 For example:
-- `docs/user-auth-tech-design.md`
-- `docs/payment-service-tech-design.md`
-- `docs/data-pipeline-tech-design.md`
+- `docs/user-auth/tech-design.md`
+- `docs/payment-service/tech-design.md`
+- `docs/data-pipeline/tech-design.md`
 
 ### Step 4: Fill in the Content
 
 When generating the document, ensure that:
 1. **All sections from the template are included** — do not skip sections; mark them as "N/A" if not applicable
 2. **The overview is concise** — 2-3 sentences maximum
-3. **Architecture diagrams** use ASCII art or reference image files stored in `docs/images/`
+3. **Architecture diagrams** use ASCII art or reference image files stored in `docs/<feature-name>/images/`
 4. **API designs** include request/response examples with realistic data
 5. **Security considerations** are always addressed, even for internal tools
 6. **Open questions** capture any unresolved decisions that need input from stakeholders

README.md

@@ -13,7 +13,7 @@
 1. 在支持AI Agent模式的IDE中打开此仓库（例如：VS Code + GitHub Copilot）
 2. 进入 Agent 模式（在 GitHub Copilot Chat 中选择 `Agent` 模式）
 3. 向 Agent 描述你的技术设计需求，例如：
-   > "请根据 `templates/tech-design-template.md` 模板，为 [你的功能] 创建一个技术设计文档，保存到 `docs/` 目录。"
+   > "请根据 `templates/tech-design-template.md` 模板，为 [你的功能] 创建一个技术设计文档，保存到 `docs/[功能名称]/tech-design.md`。"
 4. Agent 会自动生成技术设计文档并保存到 `docs/` 目录下
 
 ### 目录结构
@@ -25,15 +25,16 @@ tech-design/
 ├── templates/
 │   └── tech-design-template.md   # 技术设计文档模板
 ├── docs/
-│   └── sample-tech-design.md     # 示例技术设计文档
+│   └── <模块名称>/               # 每个模块单独一个文件夹
+│       └── tech-design.md        # 该模块的设计文档
 └── README.md
 ```
 
 ### 模板使用说明
 
 - **模板文件**：`templates/tech-design-template.md`
-- **文档存放**：所有生成的技术设计文档保存在 `docs/` 目录
-- **命名规范**：`docs/<功能名称>-tech-design.md`，例如 `docs/user-auth-tech-design.md`
+- **文档存放**：每个模块的设计文档单独保存在 `docs/<模块名称>/` 文件夹中
+- **命名规范**：`docs/<模块名称>/tech-design.md`，例如 `docs/user-auth/tech-design.md`
 
 ---
 
@@ -46,7 +47,7 @@ This repository is used to create technical design documents using AI Agent mode
 1. Open this repository in an IDE that supports AI Agent mode (e.g., VS Code + GitHub Copilot)
 2. Switch to Agent mode (select `Agent` mode in GitHub Copilot Chat)
 3. Describe your technical design requirements to the Agent, for example:
-   > "Please create a technical design document for [your feature] based on the `templates/tech-design-template.md` template, and save it to the `docs/` directory."
+   > "Please create a technical design document for [your feature] based on the `templates/tech-design-template.md` template, and save it to `docs/[feature-name]/tech-design.md`."
 4. The Agent will automatically generate the technical design document and save it to the `docs/` directory
 
 ### Directory Structure
@@ -58,12 +59,13 @@ tech-design/
 ├── templates/
 │   └── tech-design-template.md   # Technical design document template
 ├── docs/
-│   └── sample-tech-design.md     # Sample technical design document
+│   └── <module-name>/            # One folder per module
+│       └── tech-design.md        # Design document for that module
 └── README.md
 ```
 
 ### Template Usage
 
 - **Template file**: `templates/tech-design-template.md`
-- **Document storage**: All generated technical design documents are saved in the `docs/` directory
-- **Naming convention**: `docs/<feature-name>-tech-design.md`, e.g., `docs/user-auth-tech-design.md`
+- **Document storage**: Each module's design document is stored in its own folder under `docs/<module-name>/`
+- **Naming convention**: `docs/<module-name>/tech-design.md`, e.g., `docs/user-auth/tech-design.md`