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/40-workflows/pm-workflow.md

@@ -0,0 +1,15 @@
+---
+id: PM-WORKFLOW-AI-RD
+type: workflow
+status: draft
+created: 2026-06-29
+---
+
+# PM 工作流
+
+1. 收集原始输入，创建 INTAKE。
+2. 使用 `pm-requirement-review` 评审需求。
+3. 补齐问题后，使用 `pm-requirement-refine` 生成 UR、RA、SA。
+4. 更新 case 的 `traceability.md`。
+5. 进入 Gate 1 用户需求评审。
+6. 评审通过后交给 SE。