feat: 清理 control_node + 引入 task 一等公民

- control_node 标注 DEPRECATED：保留目录壳子供未来远程探针节点复用，删除调用路径与相关测试
- 新增 task 表：极简元数据持久化 regulatory_node 完成的短任务（出报告/写文件/查询整理）
- regulatory_node 自标注：MessageResponse 扩展 task_action/title/summary，_run 末尾非阻塞落库
- query_task_list 改查 task 表，符合用户对"任务列表"的直觉，与 workflow 体系解耦
- 新增 /api/v1/task/list|/{id} 只读 API（task 由 regulatory 内部触发，不开放对外创建）

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

alembic/versions/2026_06_17_0001-0011_task_table.py

@@ -0,0 +1,46 @@
+"""add task table for regulatory_node short tasks
+
+Revision ID: 0011
+Revises: 0010
+Create Date: 2026-06-17
+"""
+
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy.dialects.postgresql import JSONB
+
+revision = "0011"
+down_revision = "0010"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    op.create_table(
+        "task",
+        sa.Column("task_id", sa.String(64), primary_key=True),
+        sa.Column("user_id", sa.String(64), index=True, nullable=False),
+        sa.Column("chat_id", sa.String(64), index=True, nullable=True),
+        sa.Column("command", sa.Text(), nullable=False),
+        sa.Column("title", sa.String(255), nullable=False),
+        sa.Column(
+            "status", sa.String(20), index=True, server_default="completed"
+        ),
+        sa.Column("result_summary", sa.Text(), nullable=True),
+        sa.Column("artifact_refs", JSONB, nullable=True),
+        sa.Column(
+            "created_at",
+            sa.DateTime(timezone=True),
+            server_default=sa.func.now(),
+            index=True,
+        ),
+        sa.Column(
+            "updated_at",
+            sa.DateTime(timezone=True),
+            server_default=sa.func.now(),
+        ),
+    )
+
+
+def downgrade() -> None:
+    op.drop_table("task")