test: fix structured reask evidence and live coverage conclusions

tests/e2e/conftest.py

@@ -51,6 +51,8 @@ class _Attempt:
 
     call_id: str
     exchanges: list[_Exchange] = field(default_factory=list)
+    messages_digest: str | None = None
+    messages_valid: bool = False
 
 
 class LiveCapture:
@@ -66,6 +68,14 @@ class LiveCapture:
                 raise ValueError("取证矩阵缺少必需预期或混用 chat/embed")
             if not isinstance(expected["control"], dict):
                 raise ValueError("control 必须是显式对象")
+            if "structured_max_retries" in expected and (
+                "stream" not in expected
+                or type(expected["structured_max_retries"]) is not int
+                or expected["structured_max_retries"] < 0
+                or type(expected.get("messages_prefix_length")) is not int
+                or expected["messages_prefix_length"] < 1
+            ):
+                raise ValueError("结构化预期缺少合法前缀长度或重问预算")
         self._expectations = {name: dict(value) for name, value in expectations.items()}
         self._round: ContextVar[tuple[str, str]] = ContextVar("live_round")
         self._attempt: ContextVar[_Attempt] = ContextVar("live_attempt")
@@ -146,6 +156,29 @@ class LiveCapture:
                             self._notes[key].append("原始 JSON 身份无法独立解析")
         return HttpEvidence(call_id, exchange.checks, status, body, identity)
 
+    def observe_messages(self, source: SourceConfig, messages: list[dict[str, Any]]) -> None:
+        """先验前缀／反馈契约与委托摘要分开；摘要仅验证 HTTP 序列化保真。"""
+        expected = self._expectations[source.name]
+        if "structured_max_retries" not in expected:
+            return
+        attempt = self._attempt.get()
+        prefix_length = expected["messages_prefix_length"]
+        feedback = messages[prefix_length:]
+        attempt.messages_digest = messages_digest(messages)
+        attempt.messages_valid = (
+            (not feedback or bool(self._records[self._round.get()]))
+            and messages_digest(messages[:prefix_length]) == expected["messages_digest"]
+            and len(feedback) % 2 == 0
+            and len(feedback) <= 2 * expected["structured_max_retries"]
+            and all(
+                isinstance(message, dict)
+                and set(message) == {"role", "content"}
+                and message["role"] == ("assistant" if index % 2 == 0 else "user")
+                and isinstance(message["content"], str)
+                for index, message in enumerate(feedback)
+            )
+        )
+
     def client_factory(self, source: SourceConfig) -> httpx.AsyncClient:
         """鉴权仅内存比较；沿已校验源 timeout/trust_env。"""
         expected = self._expectations[source.name]
@@ -176,8 +209,13 @@ class LiveCapture:
                 "model": payload.get("model") == expected["model"],
                 "authorization": request.headers.get("Authorization") == f"Bearer {source.api_key}",
                 "control": control == expected["control"],
-                "messages_digest": messages_digest(payload.get("messages", payload.get("input")))
-                == expected["messages_digest"],
+                "messages_digest": (
+                    attempt.messages_valid
+                    and messages_digest(payload.get("messages")) == attempt.messages_digest
+                    if "structured_max_retries" in expected
+                    else messages_digest(payload.get("messages", payload.get("input")))
+                    == expected["messages_digest"]
+                ),
             }
             if "stream" in expected:
                 checks["stream"] = payload.get("stream") is expected["stream"] and (
@@ -255,6 +293,7 @@ class ObservedTransport:
     ) -> TransportResult:
         """与生产端口逐参数同签名。"""
         with self._capture.attempt_context(call_id):
+            self._capture.observe_messages(source, messages)
             return await self._transport.complete(
                 messages=messages,
                 source=source,
@@ -315,6 +354,7 @@ def chat_expectations(
     messages: list[dict[str, Any]],
     stream: bool,
     controls: Mapping[str, dict[str, Any]],
+    structured_max_retries: int | None = None,
 ) -> dict[str, dict[str, Any]]:
     """URL 从源配置声明，控制片段必须由矩阵独立给出。"""
     result = {}
@@ -330,6 +370,10 @@ def chat_expectations(
             "control": controls[source.name],
             "messages_digest": messages_digest(messages),
         }
+        if structured_max_retries is not None:
+            result[source.name].update(
+                messages_prefix_length=len(messages), structured_max_retries=structured_max_retries
+            )
     return result