完整实现 Swarm 多智能体协作系统

- 新增 CLIPluginAdapter 统一接口 (backend/app/core/agent_adapter.py)
- 新增 LLM 服务层，支持 Anthropic/OpenAI/DeepSeek/Ollama (backend/app/services/llm_service.py)
- 新增 Agent 执行引擎，支持文件锁自动管理 (backend/app/services/agent_executor.py)
- 新增 NativeLLMAgent 原生 LLM 适配器 (backend/app/adapters/native_llm_agent.py)
- 新增进程管理器 (backend/app/services/process_manager.py)
- 新增 Agent 控制 API (backend/app/routers/agents_control.py)
- 新增 WebSocket 实时通信 (backend/app/routers/websocket.py)
- 更新前端 AgentsPage，支持启动/停止 Agent
- 测试通过：Agent 启动、批量操作、栅栏同步

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

.doc/workflow/example.yaml

@@ -0,0 +1,25 @@
+# 示例工作流定义
+workflow_id: "example_project"
+name: "示例项目工作流"
+description: "展示多智能体协作的典型工作流"
+
+meetings:
+  - meeting_id: "requirements-review"
+    title: "需求评审"
+    attendees: ["claude-001", "kimi-002"]
+    depends_on: []
+
+  - meeting_id: "design-review"
+    title: "设计评审"
+    attendees: ["claude-001", "opencode-003"]
+    depends_on: ["requirements-review"]
+
+  - meeting_id: "implementation-planning"
+    title: "实现计划"
+    attendees: ["claude-001", "kimi-002", "opencode-003"]
+    depends_on: ["design-review"]
+
+  - meeting_id: "code-review"
+    title: "代码评审"
+    attendees: ["claude-001", "opencode-003"]
+    depends_on: ["implementation-planning"]