feat(app): 移除内置agents并添加CORS支持和技能上传优化

移除了agents/registry.json中的所有内置agents配置，将agents数组清空。
为web应用添加了CORS中间件支持，允许指定的前端地址跨域访问。
重构了技能上传功能，增加了LLM重写机制，自动规范化上传的技能格式。
新增了工具名称提取逻辑，从技能正文中自动识别Required Tools段落。
更新了技能学习候选者和草稿的载荷结构，添加评估报告统计信息。
修改了意图路由技能的说明，改进任务状态管理逻辑。

app-instance/backend/tests/unit/test_tool_assembler.py

@@ -102,6 +102,58 @@ tools:
     assert [spec.name for spec in selected] == ["memory", "terminal", "search_files"]
 
 
+def test_tool_assembler_uses_required_tools_section_when_frontmatter_omits_tools(tmp_path: Path) -> None:
+    skill_dir = tmp_path / "skills" / "docker-debug"
+    skill_dir.mkdir(parents=True)
+    (skill_dir / "SKILL.md").write_text(
+        """---
+name: docker-debug
+description: Debug Docker issues.
+---
+
+# Docker Debug
+
+## Overview
+
+Debug Docker issues.
+
+## Required Tools
+
+- `terminal`
+- `search_files`
+
+## Workflow
+
+Inspect logs and search related files.
+""",
+        encoding="utf-8",
+    )
+
+    registry = ToolRegistry()
+    registry.register(DummyTool("memory", toolset="memory", always_available=True))
+    registry.register(DummyTool("terminal", toolset="shell"))
+    registry.register(DummyTool("search_files", toolset="file"))
+    registry.register(DummyTool("echo", toolset="debug"))
+
+    assembler = ToolAssembler(retriever=StaticRetriever())
+    loader = SkillsLoader(tmp_path)
+    record = loader.get_skill_record("docker-debug")
+    assert record is not None
+    assert record.tool_hints == ["terminal", "search_files"]
+
+    selected = asyncio.run(
+        assembler.assemble(
+            task_description="排查 Docker 容器日志",
+            registry=registry,
+            skills_loader=loader,
+            activated_skills=[SkillContext(name="docker-debug", content="", tool_hints=record.tool_hints)],
+            top_k=1,
+        )
+    )
+
+    assert [spec.name for spec in selected] == ["memory", "terminal", "search_files", "echo"]
+
+
 def test_embedding_fallback_can_return_all_or_top_k() -> None:
     candidates = [{"name": f"tool_{index}", "description": "", "input_schema": "{}"} for index in range(3)]
     retriever = EmbeddingRetriever(api_key_env="MISSING_EMBEDDING_KEY", api_base_env="MISSING_EMBEDDING_BASE")