feat(toolset): 工具系统重构为 toolset 统一管理，新增系统预置工具集

将工具管理从"agent 挂单个 tool"改为"agent 挂 toolset"模式：
- 三个系统预置工具集（system_basic/system_chat/system_workflow）入 DB
- 新增 send_file 工具（系统对话工具集）、修复 approval actor 调用 bug
- 后端 agent 加载全部走 toolset 链路，移除 load_tools_from_list
- 前端工具集中心卡片展示 + agent 配置改为 toolset 多选
- resource API 增加 category 过滤与系统 toolset 保护

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

kilostar/plugin/tool_plugin/send_file/send_file.py

@@ -0,0 +1,60 @@
+#  Copyright 2026 zhaoxi826
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#       http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+
+import json
+from kilostar.plugin.tool_plugin.base_tool import BaseToolData
+from kilostar.utils.ray_hook import ray_actor_hook
+from typing import List, Literal, Dict
+
+
+class SendFileToolData(BaseToolData):
+    """``send_file`` 工具元数据：把 agent 生成的文件作为附件推送到对话窗口。"""
+
+    is_system: bool = True
+    action_scope: List[
+        Literal[
+            "control_node",
+            "consciousness_node",
+            "regulatory_node",
+            "growth_node",
+            "",
+        ]
+    ] = []
+    config_args: Dict[str, str] = {}
+    category: str = "system"
+
+
+async def send_file(filename: str, content: str, trace_id: str) -> str:
+    """把 agent 生成的文件作为附件发送给当前对话窗口。
+
+    通过 global_workflow_manager 的 pending 队列推送一条带特殊前缀的 JSON 消息，
+    前端识别后渲染为可下载的文件卡片。
+
+    Args:
+        filename: 文件名（含扩展名），如 "report.md" / "main.py"
+        content: 文件内容（UTF-8 文本）
+        trace_id: 当前会话/工作流的 trace_id
+
+    Returns:
+        发送结果说明
+    """
+    payload = json.dumps(
+        {"type": "file", "filename": filename, "content": content},
+        ensure_ascii=False,
+    )
+    actor_list = ray_actor_hook("global_workflow_manager")
+    await actor_list.global_workflow_manager.put_pending.remote(
+        trace_id, f"__FILE__{payload}"
+    )
+    return f"已发送文件: {filename}"