feat: add frontend development guidelines and structure documentation

- Introduced API guidelines for interface contracts and request handling.
- Added design tokens usage guidelines for consistent styling across the project.
- Established DTO guidelines for defining request parameters and response data types.
- Created frontend structure guidelines to clarify directory organization and code placement rules.
- Compiled a comprehensive frontend development guideline document covering various aspects of the development process.
- Implemented quality guidelines to ensure code maintainability and adherence to best practices.

AI-RD-Workflow/50-cases/REQ-20260629-001-example/05-test/TC-20260629-001.md

@@ -0,0 +1,21 @@
+---
+id: TC-20260629-001
+case_id: REQ-20260629-001-example
+type: test-case
+stage: test
+owner_role: QA
+status: draft
+source_ids:
+  - TP-20260629-001
+derived_ids: []
+created: 2026-06-29
+updated: 2026-06-29
+---
+
+# 测试用例：目录骨架
+
+| 用例 ID | 类型 | 来源 ID | 前置条件 | 步骤 | 预期结果 | 优先级 |
+| --- | --- | --- | --- | --- | --- | --- |
+| TC-20260629-001-01 | positive | DS-20260629-001 | vault 可访问 | 枚举 `AI Coding/AI-RD-Workflow/` | 核心目录存在 | P0 |
+| TC-20260629-001-02 | positive | DS-20260629-001 | 文件已创建 | 检查 `50-cases/REQ-20260629-001-example/traceability.md` | 能看到从 INTAKE 到 TC 的链路 | P0 |
+| TC-20260629-001-03 | boundary | DR-20260629-001 | 已有 `AI Coding` 内容 | 检查现有目录 | 现有文件未被修改 | P1 |

AI-RD-Workflow/50-cases/REQ-20260629-001-example/05-test/TP-20260629-001.md

@@ -0,0 +1,32 @@
+---
+id: TP-20260629-001
+case_id: REQ-20260629-001-example
+type: test-plan
+stage: test
+owner_role: QA
+status: draft
+source_ids:
+  - DS-20260629-001
+derived_ids:
+  - TC-20260629-001
+created: 2026-06-29
+updated: 2026-06-29
+---
+
+# 测试计划：目录骨架
+
+## 测试范围
+
+- 目录结构。
+- 核心文档。
+- 示例 case 追踪链路。
+
+## 测试策略
+
+通过文件枚举检查结构，通过人工阅读检查文档是否可继续迭代。
+
+## 准出条件
+
+- 关键目录和文件存在。
+- 示例 case 中每个阶段至少有一个 artifact。
+- `traceability.md` 能表达上游和下游关系。