chore: T-P-1 工作区收敛——并行会话成果与历史未入库文件整理入库

- 入库历史遗漏源码/测试：router_system 9 模块（agent/executors/inference/knowledge/
  memory/planner/skills/trace）、tests 11 个测试文件、config/knowledge 领域知识
- 入库根目录方案文档（v2/v3/可行性×2）、references 文献（arxiv 14-18/cnki_open/
  参考文献清单）、research 论文素材（routerarena/paper/中文文献 PDF）
- 前端构建产物刷新（新 hash）；webapp 误写文档删除
- gitignore 增补：deepseek-harness、research/_refs、.mimosa/.zcode、网关日志/pid、
  临时调试脚本、tests/e2e/node_modules、AI代理功能开发/prefix
- 基线确认：318 passed

tests/test_dag.py

@@ -0,0 +1,63 @@
+"""黑板 / DAG（WorkingMemory / TaskGraph）单元测试。"""
+from router_system.memory import TaskGraph, TaskNode, WorkingMemory
+
+
+def _graph():
+    g = TaskGraph()
+    g.add_node(TaskNode(id="a", kind="analyze", domain="code", query="q"))
+    g.add_node(TaskNode(id="b", kind="design", domain="code", query="q", deps=["a"]))
+    g.add_node(TaskNode(id="c", kind="implement", domain="code", query="q", deps=["b"]))
+    return g
+
+
+def test_topo_order_respects_deps():
+    g = _graph()
+    order = [n.id for n in g.topo_order()]
+    assert order.index("a") < order.index("b") < order.index("c")
+
+
+def test_cycle_fallback_no_crash():
+    g = TaskGraph()
+    g.add_node(TaskNode(id="x", kind="solve", domain="m", query="q", deps=["y"]))
+    g.add_node(TaskNode(id="y", kind="solve", domain="m", query="q", deps=["x"]))
+    order = [n.id for n in g.topo_order()]
+    assert set(order) == {"x", "y"}
+
+
+def test_failed_and_all_done():
+    g = _graph()
+    assert g.all_done() is False
+    for n in g.nodes():
+        n.status = "done"
+    assert g.all_done() is True
+    g.get("a").status = "failed"
+    assert [n.id for n in g.failed()] == ["a"]
+
+
+def test_merge_order():
+    mem = WorkingMemory()
+    mem.write_section("s1", "第一部分")
+    mem.write_section("s2", "第二部分")
+    assert mem.merge(["s1", "s2"]) == "第一部分\n\n第二部分"
+    # 指定顺序可调换
+    assert mem.merge(["s2", "s1"]) == "第二部分\n\n第一部分"
+    # 无顺序 → 写入顺序
+    assert mem.merge() == "第一部分\n\n第二部分"
+
+
+def test_overwrite_fact_records_trace():
+    mem = WorkingMemory()
+    mem.write_fact("k", "v1", rule_id="r1")
+    mem.write_fact("k", "v2", rule_id="r2")
+    assert mem.get_fact("k") == "v2"
+    assert any(t.startswith("overwrite:k@r2") for t in mem.trace)
+
+
+def test_duplicate_node_id_rejected():
+    g = TaskGraph()
+    g.add_node(TaskNode(id="a", kind="solve", domain="m", query="q"))
+    try:
+        g.add_node(TaskNode(id="a", kind="solve", domain="m", query="q"))
+        assert False, "重复节点 id 应报错"
+    except ValueError:
+        pass