初始化 Makelore 项目协作文档

需求：为客户端修复任务建立独立 worktree 所有权与项目记忆门禁。

实现：引入标准 .project-docs 模板，不修改现有客户端业务代码。

.project-docs/20-architecture/system-overview.md

@@ -0,0 +1,22 @@
+# System Overview
+
+## Current Architecture
+
+{short description of the current system shape}
+
+## Main Components
+
+| Component | Responsibility | Notes |
+|---|---|---|
+
+## Important Boundaries
+
+- {boundary that future work should respect}
+
+## Related Decisions
+
+- {ADR reference}
+
+## Last Updated
+
+{YYYY-MM-DD}