chore: remove unused dump_openai_response helper and its tests

The dump_openai_response function in client.py was never called from
production code; only the dedicated unit test exercised it. Drop the
helper, its test, and the now-unused json imports so the surface area
matches what is actually wired into the nodes.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

client.py

@@ -1,7 +1,6 @@
 from __future__ import annotations
 
 import base64
-import json
 import math
 import re
 import secrets
@@ -243,16 +242,6 @@ def extract_responses_text(response: Any) -> str:
     return ""
 
 
-def dump_openai_response(response: Any) -> str:
-    if hasattr(response, "model_dump"):
-        return json.dumps(response.model_dump(), indent=2, default=str)
-    if hasattr(response, "to_dict"):
-        return json.dumps(response.to_dict(), indent=2, default=str)
-    if isinstance(response, dict):
-        return json.dumps(response, indent=2, default=str)
-    return str(response)
-
-
 _THINK_BLOCK_RE = re.compile(r"<think>.*?</think>", flags=re.IGNORECASE | re.DOTALL)
 _THINK_START_RE = re.compile(r"<think>.*$", flags=re.IGNORECASE | re.DOTALL)
 

tests/test_client_full.py

@@ -2,7 +2,6 @@ from __future__ import annotations
 
 import base64
 from io import BytesIO
-import json
 import sys
 import types
 
@@ -183,25 +182,6 @@ def test_extract_responses_text_variants() -> None:
     assert client.extract_responses_text(ns(output_text="", output=[])) == ""
 
 
-def test_dump_openai_response_branches() -> None:
-    class WithModelDump:
-        def model_dump(self):
-            return {"a": 1}
-
-    class WithToDict:
-        def to_dict(self):
-            return {"b": 2}
-
-    class Plain:
-        def __str__(self) -> str:
-            return "plain-response"
-
-    assert json.loads(client.dump_openai_response(WithModelDump())) == {"a": 1}
-    assert json.loads(client.dump_openai_response(WithToDict())) == {"b": 2}
-    assert json.loads(client.dump_openai_response({"c": 3})) == {"c": 3}
-    assert client.dump_openai_response(Plain()) == "plain-response"
-
-
 def test_strip_think_content_case_insensitive_and_multiple() -> None:
     text = "A\n<THINK>hidden-1</THINK>\nB\n<think>hidden-2</think>\nC"
     assert client.strip_think_content(text) == "A\n\nB\n\nC"