fix(codex): size and propagate timeouts for Responses-API requests; lower stale defaults

Codex / Responses-API requests had three latent timeout bugs that combined
into the long silent hangs reported on #21444:

1. The non-stream stale-call detector estimated context tokens from
   ``api_kwargs["messages"]`` only. Codex / Responses-API payloads carry
   their conversational load in ``input`` (with ``instructions`` and
   ``tools``), so every Codex turn logged ``context=~0 tokens`` and the
   detector never applied its >50k / >100k tier bumps.

2. ``providers.<id>.request_timeout_seconds`` was silently dropped on the
   main Codex path. The chat_completions path and the auxiliary Codex
   adapter both forwarded it; the main path skipped it through three
   places (``build_api_kwargs``, ``ResponsesApiTransport.build_kwargs``,
   ``_preflight_codex_api_kwargs``).

3. The streaming stale detector had the same payload-shape bug for
   ``codex_responses`` requests, which route through the non-streaming
   detector (it's the path that emits the user-facing
   "No response from provider for 300s (non-streaming, ...)" warning that
   reporters keep pasting).

This commit:

- Adds ``estimate_request_context_tokens`` in ``chat_completion_helpers``,
  used by both the non-stream and stream detectors. Handles ``messages``
  (Chat Completions), ``input + instructions + tools`` (Responses API),
  bare lists, and an unknown-dict fallback.
- Forwards ``timeout`` through ``ResponsesApiTransport.build_kwargs``
  and ``_preflight_codex_api_kwargs`` (with guards against
  zero/negative/inf/bool values), and wires
  ``_resolved_api_call_timeout()`` into the Codex branch of
  ``build_api_kwargs``.
- Lowers the implicit non-stream stale defaults so fallback providers
  kick in faster when upstream stalls:
    * base   300s -> 90s
    * >50k   450s -> 150s
    * >100k  600s -> 240s
  These only apply when the user has *not* set
  ``providers.<id>.stale_timeout_seconds`` or
  ``HERMES_API_CALL_STALE_TIMEOUT``. Explicit config still wins.
- Adds regression tests for the estimator shapes, the new defaults, the
  context-tier scaling, transport timeout pass-through, and preflight
  timeout pass-through / rejection of invalid values.

Closes #21444
Supersedes #21652 #24126 #31855

Co-authored-by: Hoang V. Pham <26063003+hehehe0803@users.noreply.github.com>

tests/run_agent/test_openai_client_lifecycle.py

@@ -105,7 +105,7 @@ def test_stale_non_stream_close_is_single_owner(monkeypatch):
     monkeypatch.setattr(run_agent, "OpenAI", factory)
 
     agent = _build_agent()
-    agent._compute_non_stream_stale_timeout = lambda _messages: 0.01
+    agent._compute_non_stream_stale_timeout = lambda api_payload: 0.01
 
     with pytest.raises(APIConnectionError):
         agent._interruptible_api_call({"model": agent.model, "messages": []})

tests/run_agent/test_run_agent_codex_responses.py

@@ -306,7 +306,10 @@ def test_build_api_kwargs_codex(monkeypatch):
     assert kwargs["parallel_tool_calls"] is True
     assert isinstance(kwargs["prompt_cache_key"], str)
     assert len(kwargs["prompt_cache_key"]) > 0
-    assert "timeout" not in kwargs
+    # ``timeout`` is now wired from ``_resolved_api_call_timeout`` (default 1800s)
+    # so per-provider ``request_timeout_seconds`` actually reaches the SDK.
+    assert isinstance(kwargs.get("timeout"), float)
+    assert kwargs["timeout"] > 0
     assert "max_tokens" not in kwargs
     assert "extra_body" not in kwargs
 
@@ -1053,6 +1056,29 @@ def test_preflight_codex_api_kwargs_allows_service_tier(monkeypatch):
     assert result["service_tier"] == "priority"
 
 
+def test_preflight_codex_api_kwargs_preserves_positive_timeout(monkeypatch):
+    """Positive numeric timeouts survive preflight so the SDK honors them."""
+    agent = _build_agent(monkeypatch)
+    kwargs = _codex_request_kwargs()
+    kwargs["timeout"] = 600.0
+
+    from agent.codex_responses_adapter import _preflight_codex_api_kwargs
+    result = _preflight_codex_api_kwargs(kwargs)
+    assert result["timeout"] == 600.0
+
+
+def test_preflight_codex_api_kwargs_drops_invalid_timeout(monkeypatch):
+    """Zero, negative, inf, and booleans are all dropped — not passed to SDK."""
+    agent = _build_agent(monkeypatch)
+    from agent.codex_responses_adapter import _preflight_codex_api_kwargs
+
+    for bad in (0, -1, float("inf"), True, False, "300", None):
+        kwargs = _codex_request_kwargs()
+        kwargs["timeout"] = bad
+        result = _preflight_codex_api_kwargs(kwargs)
+        assert "timeout" not in result, f"timeout={bad!r} should be dropped"
+
+
 def test_run_conversation_codex_replay_payload_keeps_call_id(monkeypatch):
     agent = _build_agent(monkeypatch)
     responses = [_codex_tool_call_response(), _codex_message_response("done")]