feat: preserve governed OpenAI tool messages in 1.4.0

Add faithful single-choice chat results, tool stream activity, error-frame retries, and isolated protocol caching.

Reject empty cached completions with the same value predicate as transport, add regression coverage, and adopt Apache-2.0.

research-wiki/graph/edges.json

@@ -225,6 +225,21 @@
       "id": "finding:2026-09-09-134-thinking-contracts-validation",
       "label": "1.3.4 T0–T4 与 T7 确定性验证",
       "type": "finding"
+    },
+    {
+      "id": "design:2026-10-01-issue29-openai-fidelity-design",
+      "label": "OpenAI消息保真设计",
+      "type": "design"
+    },
+    {
+      "id": "plan:2026-10-01-issue29-openai-fidelity",
+      "label": "OpenAI消息保真实现计划",
+      "type": "plan"
+    },
+    {
+      "id": "review:2026-10-01-issue29-cache-review",
+      "label": "保真缓存审查修复与1.4.0准备",
+      "type": "review"
     }
   ],
   "links": [
@@ -472,6 +487,27 @@
       "relation": "implements",
       "evidence": "1.3.5 逻辑调用统计与结构化失败诊断实施计划落地已批准设计",
       "added": "2026-09-09T13:42:00.298915+00:00"
+    },
+    {
+      "source": "plan:2026-10-01-issue29-openai-fidelity",
+      "target": "design:2026-10-01-issue29-openai-fidelity-design",
+      "relation": "implements",
+      "evidence": "已批准方向与独立审查P1/P2修订",
+      "added": "2026-10-01T17:52:42.425248+00:00"
+    },
+    {
+      "source": "schema:llm-calls",
+      "target": "design:2026-10-01-issue29-openai-fidelity-design",
+      "relation": "implements",
+      "evidence": "复用既有单出口与schema，无新增列；工具error为attempt失败",
+      "added": "2026-10-01T17:52:43.831331+00:00"
+    },
+    {
+      "source": "review:2026-10-01-issue29-cache-review",
+      "target": "design:2026-10-01-issue29-openai-fidelity-design",
+      "relation": "informs",
+      "evidence": "统一缓存与transport的有效产物判据，保持内核依赖边界",
+      "added": "2026-10-01T18:27:16.434742+00:00"
     }
   ]
 }