fix(conversion): OpenAI CLI 流式转换 tool 调用与文本输出 block index 不再复用

引入统一的 block index 分配器（_allocate_block_index / _ensure_text_block_index），
避免工具调用后紧跟文本输出时 Claude block index 冲突。

src/core/api_format/conversion/normalizers/openai_cli.py

@@ -596,6 +596,8 @@ class OpenAICliNormalizer(FormatNormalizer):
                 ss["message_started"] = True
                 ss.setdefault("text_block_started", False)
                 ss.setdefault("text_block_stopped", False)
+                ss.setdefault("text_block_index", None)
+                ss.setdefault("next_block_index", 0)
                 events.append(MessageStartEvent(message_id=msg_id, model=model))
 
         handler = self._CHUNK_HANDLERS.get(etype)
@@ -626,10 +628,16 @@ class OpenAICliNormalizer(FormatNormalizer):
             delta_text = str(delta.get("text") or "")
 
         if delta_text:
+            text_block_index = self._ensure_text_block_index(ss)
             if not ss.get("text_block_started"):
                 ss["text_block_started"] = True
-                events.append(ContentBlockStartEvent(block_index=0, block_type=ContentType.TEXT))
-            events.append(ContentDeltaEvent(block_index=0, text_delta=delta_text))
+                events.append(
+                    ContentBlockStartEvent(
+                        block_index=text_block_index,
+                        block_type=ContentType.TEXT,
+                    )
+                )
+            events.append(ContentDeltaEvent(block_index=text_block_index, text_delta=delta_text))
         return events
 
     def _handle_output_text_done(
@@ -638,7 +646,7 @@ class OpenAICliNormalizer(FormatNormalizer):
         events: list[InternalStreamEvent] = []
         if ss.get("text_block_started") and not ss.get("text_block_stopped"):
             ss["text_block_stopped"] = True
-            events.append(ContentBlockStopEvent(block_index=0))
+            events.append(ContentBlockStopEvent(block_index=self._ensure_text_block_index(ss)))
         return events
 
     def _handle_response_completed(
@@ -651,7 +659,7 @@ class OpenAICliNormalizer(FormatNormalizer):
 
         if ss.get("text_block_started") and not ss.get("text_block_stopped"):
             ss["text_block_stopped"] = True
-            events.append(ContentBlockStopEvent(block_index=0))
+            events.append(ContentBlockStopEvent(block_index=self._ensure_text_block_index(ss)))
 
         # 补齐所有已开始但未结束的 tool_call block
         active_tools = ss.get("active_tool_blocks")
@@ -701,7 +709,7 @@ class OpenAICliNormalizer(FormatNormalizer):
                 item_id = str(item.get("id") or "")
                 tool_id = str(item.get("call_id") or item.get("id") or "")
                 tool_name = str(item.get("name") or "")
-                block_index = int(ss.get("block_index", 0))
+                block_index = self._allocate_block_index(ss)
 
                 # 先注册别名，再 resolve，确保后续 delta 能正确映射
                 self._register_tool_alias(
@@ -736,7 +744,6 @@ class OpenAICliNormalizer(FormatNormalizer):
                         ss=ss,
                     )
                 )
-                ss["block_index"] = block_index + 1
         return events
 
     def _handle_output_item_done(
@@ -754,7 +761,7 @@ class OpenAICliNormalizer(FormatNormalizer):
                     ss=ss,
                 )
                 active_tools = ss.get("active_tool_blocks", {})
-                block_index = active_tools.pop(tool_id, ss.get("block_index", 1) - 1)
+                block_index = active_tools.pop(tool_id, self._last_block_index(ss))
                 events.extend(
                     self._sync_tool_arguments_snapshot(
                         tool_id=tool_id,
@@ -778,7 +785,7 @@ class OpenAICliNormalizer(FormatNormalizer):
                 ss,
             )
             active_tools = ss.get("active_tool_blocks", {})
-            block_index = active_tools.get(tool_id, ss.get("block_index", 1) - 1)
+            block_index = active_tools.get(tool_id, self._last_block_index(ss))
 
             # 累积参数
             tool_calls = ss.setdefault("tool_calls", {})
@@ -802,7 +809,7 @@ class OpenAICliNormalizer(FormatNormalizer):
             ss,
         )
         active_tools = ss.get("active_tool_blocks", {})
-        block_index = int(active_tools.get(tool_id, ss.get("block_index", 1) - 1))
+        block_index = int(active_tools.get(tool_id, self._last_block_index(ss)))
         return self._sync_tool_arguments_snapshot(
             tool_id=tool_id,
             block_index=block_index,
@@ -1418,6 +1425,25 @@ class OpenAICliNormalizer(FormatNormalizer):
         ss["seq"] = seq
         return seq
 
+    @staticmethod
+    def _allocate_block_index(ss: dict[str, Any]) -> int:
+        idx = ss.get("next_block_index", 0)
+        ss["next_block_index"] = idx + 1
+        return idx
+
+    @classmethod
+    def _ensure_text_block_index(cls, ss: dict[str, Any]) -> int:
+        idx = ss.get("text_block_index")
+        if idx is not None:
+            return idx
+        idx = cls._allocate_block_index(ss)
+        ss["text_block_index"] = idx
+        return idx
+
+    @staticmethod
+    def _last_block_index(ss: dict[str, Any]) -> int:
+        return max(ss.get("next_block_index", 1) - 1, 0)
+
     def _unwrap_response_object(self, response: dict[str, Any]) -> dict[str, Any]:
         if not isinstance(response, dict):
             return {}

tests/core/api_format/conversion/test_cli_conversion.py

@@ -753,6 +753,93 @@ def test_stream_openai_cli_function_call_events() -> None:
     assert events3[-1].get("type") == "content_block_stop"
 
 
+def test_stream_openai_cli_tool_then_text_uses_distinct_claude_block_indices() -> None:
+    """Responses 工具调用后再输出文本时，Claude block index 不能复用。"""
+    reg = _make_registry_with_cli()
+    state = StreamState()
+
+    cli_chunks: list[dict[str, Any]] = [
+        {
+            "type": "response.created",
+            "response": {
+                "id": "resp_tool_then_text",
+                "object": "response",
+                "model": "gpt-5.4",
+                "status": "in_progress",
+                "output": [],
+            },
+        },
+        {
+            "type": "response.output_item.added",
+            "output_index": 0,
+            "item": {
+                "type": "function_call",
+                "call_id": "call_tool_then_text",
+                "id": "fc_tool_then_text",
+                "name": "read_file",
+                "status": "in_progress",
+                "arguments": "",
+            },
+        },
+        {
+            "type": "response.function_call_arguments.delta",
+            "output_index": 0,
+            "item_id": "fc_tool_then_text",
+            "delta": '{"path":"README.md"}',
+        },
+        {
+            "type": "response.output_text.delta",
+            "output_index": 1,
+            "item_id": "msg_tool_then_text",
+            "content_index": 0,
+            "delta": "done",
+        },
+        {
+            "type": "response.output_item.done",
+            "output_index": 0,
+            "item": {
+                "type": "function_call",
+                "call_id": "call_tool_then_text",
+                "id": "fc_tool_then_text",
+                "name": "read_file",
+                "status": "completed",
+                "arguments": '{"path":"README.md"}',
+            },
+        },
+        {
+            "type": "response.completed",
+            "response": {
+                "id": "resp_tool_then_text",
+                "object": "response",
+                "model": "gpt-5.4",
+                "status": "completed",
+                "output": [],
+                "usage": {"input_tokens": 8, "output_tokens": 4, "total_tokens": 12},
+            },
+        },
+    ]
+
+    all_events: list[dict[str, Any]] = []
+    for chunk in cli_chunks:
+        all_events.extend(reg.convert_stream_chunk(chunk, "openai:cli", "claude:cli", state=state))
+
+    starts = [e for e in all_events if e.get("type") == "content_block_start"]
+    assert len(starts) >= 2
+
+    tool_start = next(e for e in starts if (e.get("content_block") or {}).get("type") == "tool_use")
+    text_start = next(e for e in starts if (e.get("content_block") or {}).get("type") == "text")
+    assert tool_start["index"] != text_start["index"]
+
+    text_delta = next(
+        e
+        for e in all_events
+        if e.get("type") == "content_block_delta"
+        and (e.get("delta") or {}).get("type") == "text_delta"
+    )
+    assert text_delta["index"] == text_start["index"]
+    assert text_delta["index"] != tool_start["index"]
+
+
 def test_stream_openai_cli_function_call_done_without_delta_emits_full_args() -> None:
     """无 arguments.delta 时，done 快照也应补出完整 tool arguments。"""
     reg = _make_registry_with_cli()