feat: Add agent workspace system and runtime management

- Add agent core modules (agent_core, factory, registry, skill_loader)
- Add runtime system for agent execution management
- Add REST API for agents, workspaces, and runtime control
- Add process supervisor for agent lifecycle management
- Add workspace template system with agent profiles
- Add frontend RuntimeView and runtime API integration
- Add per-agent skill workspaces for smoke_fullstack run
- Refactor skill system with active/installed separation

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/workspaces/.template/AGENTS.md

@@ -0,0 +1,16 @@
+# Agent Guide
+
+## 工作流程
+1. 接收分析任务
+2. 调用相关工具/技能
+3. 生成分析报告
+4. 参与团队决策
+
+## 工具使用规范
+- 优先使用已激活的技能
+- 不确定时询问Portfolio Manager
+- 重要发现用 `/save` 记录
+
+## 记忆管理
+- 使用 `/compact` 定期压缩记忆
+- 投资经验记录在MEMORY.md