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。

agents/registry.json

@@ -1,145 +1,4 @@
 {
-  "agents": [
-    {
-      "agent_id": "researcher",
-      "capabilities": [
-        "research",
-        "analysis",
-        "source review",
-        "requirements"
-      ],
-      "created_at": "2026-05-11T03:13:06.912240+00:00",
-      "description": "Finds facts, references, constraints, and implementation options.",
-      "display_name": "Researcher",
-      "metadata": {},
-      "model": null,
-      "name": "researcher",
-      "priority": 50,
-      "provider_name": null,
-      "role": "research",
-      "skill_names": [],
-      "source": "builtin",
-      "status": "active",
-      "system_prompt": "You are a research specialist. Gather concise evidence and tradeoffs for the parent task.",
-      "tags": [
-        "planning",
-        "research"
-      ],
-      "tool_hints": [],
-      "updated_at": "2026-05-11T03:13:06.912247+00:00"
-    },
-    {
-      "agent_id": "implementer",
-      "capabilities": [
-        "implementation",
-        "coding",
-        "refactor",
-        "integration"
-      ],
-      "created_at": "2026-05-11T03:13:06.912250+00:00",
-      "description": "Builds scoped implementation slices and proposes concrete changes.",
-      "display_name": "Implementer",
-      "metadata": {},
-      "model": null,
-      "name": "implementer",
-      "priority": 45,
-      "provider_name": null,
-      "role": "implementation",
-      "skill_names": [],
-      "source": "builtin",
-      "status": "active",
-      "system_prompt": "You are an implementation specialist. Produce practical, scoped implementation output.",
-      "tags": [
-        "coding",
-        "build"
-      ],
-      "tool_hints": [],
-      "updated_at": "2026-05-11T03:13:06.912251+00:00"
-    },
-    {
-      "agent_id": "reviewer",
-      "capabilities": [
-        "review",
-        "quality",
-        "risk",
-        "verification"
-      ],
-      "created_at": "2026-05-11T03:13:06.912252+00:00",
-      "description": "Reviews plans, code, outputs, and risks before final synthesis.",
-      "display_name": "Reviewer",
-      "metadata": {},
-      "model": null,
-      "name": "reviewer",
-      "priority": 45,
-      "provider_name": null,
-      "role": "review",
-      "skill_names": [],
-      "source": "builtin",
-      "status": "active",
-      "system_prompt": "You are a review specialist. Focus on defects, missing requirements, and risks.",
-      "tags": [
-        "review",
-        "quality"
-      ],
-      "tool_hints": [],
-      "updated_at": "2026-05-11T03:13:06.912253+00:00"
-    },
-    {
-      "agent_id": "tester",
-      "capabilities": [
-        "testing",
-        "verification",
-        "regression",
-        "qa"
-      ],
-      "created_at": "2026-05-11T03:13:06.912255+00:00",
-      "description": "Designs and executes verification checks for task outputs.",
-      "display_name": "Tester",
-      "metadata": {},
-      "model": null,
-      "name": "tester",
-      "priority": 40,
-      "provider_name": null,
-      "role": "testing",
-      "skill_names": [],
-      "source": "builtin",
-      "status": "active",
-      "system_prompt": "You are a testing specialist. Identify focused checks and report pass/fail evidence.",
-      "tags": [
-        "test",
-        "quality"
-      ],
-      "tool_hints": [],
-      "updated_at": "2026-05-11T03:13:06.912256+00:00"
-    },
-    {
-      "agent_id": "documenter",
-      "capabilities": [
-        "documentation",
-        "explanation",
-        "migration notes",
-        "release notes"
-      ],
-      "created_at": "2026-05-11T03:13:06.912257+00:00",
-      "description": "Writes and reconciles user-facing and internal documentation updates.",
-      "display_name": "Documenter",
-      "metadata": {},
-      "model": null,
-      "name": "documenter",
-      "priority": 35,
-      "provider_name": null,
-      "role": "documentation",
-      "skill_names": [],
-      "source": "builtin",
-      "status": "active",
-      "system_prompt": "You are a documentation specialist. Produce concise docs aligned with the implementation.",
-      "tags": [
-        "docs",
-        "communication"
-      ],
-      "tool_hints": [],
-      "updated_at": "2026-05-11T03:13:06.912258+00:00"
-    }
-  ],
+  "agents": [],
   "version": 1
 }