docs: register the implementation plan in the research wiki

research-wiki/graph/edges.json

@@ -115,6 +115,11 @@
       "id": "design:response-observability-fields",
       "label": "响应可观测字段扩展(Issue #3)",
       "type": "design"
+    },
+    {
+      "id": "plan:response-observability-fields",
+      "label": "响应可观测字段扩展实现计划",
+      "type": "plan"
     }
   ],
   "links": [
@@ -194,6 +199,13 @@
       "relation": "implements",
       "evidence": "5 任务实现设计 §3.2 的 11 条改动项;任务排序经中间态破窗分析(先加能力→切调用点→三态生效→解绑约束)",
       "added": "2026-07-30T09:39:26.442986+00:00"
+    },
+    {
+      "source": "plan:response-observability-fields",
+      "target": "design:response-observability-fields",
+      "relation": "implements",
+      "evidence": "计划 T1-T7 逐条实现设计的 A2/B1/C1/D1 四个决策",
+      "added": "2026-07-31T11:10:03.872049+00:00"
     }
   ]
 }