feat: 初始化 SCALE OS 工程框架

- 添加 SCALE Engine 配置 (.scale/)
- 添加 OpenClaw Agent 配置 (.openclaw/)
- 添加知识文档 (AGENTS.md, TOOLS.md)
- 添加质量契约和工作流配置
- 添加 22 个工作流模板
- 添加验证脚本和门控脚本
- 添加 skills-registry 技能注册表

.scale/engineering-standards-baseline.json

@@ -0,0 +1,6 @@
+{
+  "version": 1,
+  "generatedAt": "",
+  "scope": "Legacy findings tracked separately. New findings and changed-file findings must still be fixed before completion.",
+  "findings": []
+}