feat(agents): Phase 7-10 hook system, plugins, skills, orchestration

Phase 7: Built-in Hooks (audit_log, dangerous_confirmation, security_scan)
Phase 8: Plugin system (PluginManager, PluginSandbox, PluginManifest)
Phase 9: Skills registry (SkillRegistry, local/plugin/MCP loaders)
Phase 10: TeamLeader, RemoteTransport, BackgroundTaskManager

backend/app/agents/skills/mcp_builder.py

@@ -0,0 +1,100 @@
+"""MCP Skill Builder - Phase 9.3"""
+
+from typing import Any
+
+from app.agents.skills.metadata import SkillMetadata
+
+
+class MCPSkillBuilder:
+    """MCP Skill Builder
+
+    从 MCP 服务器发现和构建 Skills。
+    """
+
+    def __init__(self):
+        self._skills: dict[str, SkillMetadata] = {}
+
+    def discover_skills_from_mcp(self, mcp_servers: list[dict[str, Any]]) -> list[SkillMetadata]:
+        """从 MCP 服务器发现 Skills
+
+        Args:
+            mcp_servers: MCP 服务器配置列表
+
+        Returns:
+            发现的 Skill 元数据列表
+        """
+        skills = []
+
+        for server in mcp_servers:
+            server_skills = self._discover_from_server(server)
+            skills.extend(server_skills)
+
+        return skills
+
+    def _discover_from_server(self, server: dict[str, Any]) -> list[SkillMetadata]:
+        """从单个 MCP 服务器发现 Skills"""
+        skills = []
+        server_name = server.get("name", "unknown")
+        tools = server.get("tools", [])
+
+        # 按工具分组
+        tool_groups: dict[str, list[str]] = {}
+        for tool in tools:
+            group = tool.get("group", "default")
+            if group not in tool_groups:
+                tool_groups[group] = []
+            tool_groups[group].append(tool)
+
+        # 为每个组创建一个 Skill
+        for group_name, group_tools in tool_groups.items():
+            skill = self._tool_to_skill(group_name, group_tools, server_name)
+            skills.append(skill)
+
+        return skills
+
+    def _tool_to_skill(self, group: str, tools: list[dict[str, Any]], server: str) -> SkillMetadata:
+        """将 MCP 工具转换为 Skill"""
+        tool_summaries = []
+        for tool in tools:
+            name = tool.get("name", "unknown")
+            description = tool.get("description", "")
+            input_schema = tool.get("inputSchema", {})
+
+            tool_summaries.append(f"### {name}\n{description}\n\nInput: {input_schema}")
+
+        content = f"""# MCP Skill: {group}
+
+来自 MCP 服务器: {server}
+
+## 工具列表
+
+{chr(10).join(tool_summaries)}
+
+## 使用说明
+
+使用这些工具前请确保理解每个工具的输入输出格式。
+"""
+
+        return SkillMetadata(
+            name=f"mcp-{server}-{group}",
+            description=f"MCP skill from {server}: {group}",
+            version="1.0.0",
+            tags=["mcp", server, group],
+            triggers=[group, server],
+            content=content,
+            source="mcp",
+            source_id=f"{server}:{group}",
+        )
+
+    def _group_to_skill(self, group: str, tools: list[str], server: str) -> SkillMetadata:
+        """将 MCP 工具组转换为 Skill"""
+        return SkillMetadata(
+            name=f"mcp-{server}-{group}",
+            description=f"MCP skill from {server}: {group}",
+            version="1.0.0",
+            tags=["mcp", server, group],
+            triggers=[group, server],
+            content=f"# {group}\n\nTools: {', '.join(tools)}",
+            source="mcp",
+            source_id=f"{server}:{group}",
+        )