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>

agent/chat_completion_helpers.py

@@ -75,6 +75,59 @@ def _ra():
     return run_agent
 
 
+def estimate_request_context_tokens(api_payload: Any) -> int:
+    """Estimate context/load tokens from an API payload, dict or messages list.
+
+    The stale-call detectors historically assumed a Chat Completions request:
+    they pulled ``api_kwargs["messages"]`` and ran a cheap char/4 estimate.
+    Codex / Responses API requests carry the conversational payload in
+    ``input`` (with additional load in ``instructions`` and ``tools``), so the
+    legacy estimator reported ~0 tokens for every Codex turn and the
+    context-tier scaling never fired.
+
+    This helper handles both shapes:
+      - bare list -> treat as Chat Completions ``messages``
+      - dict with ``messages`` -> Chat Completions (+ ``tools`` if present)
+      - dict with ``input`` -> Responses API (+ ``instructions``/``tools``)
+      - any other dict -> fall back to summing string values
+    """
+
+    def _chars(value: Any) -> int:
+        if value is None:
+            return 0
+        if isinstance(value, str):
+            return len(value)
+        return len(str(value))
+
+    def _message_chars(messages: Any) -> int:
+        if not isinstance(messages, list):
+            return _chars(messages)
+        return sum(_chars(item) for item in messages)
+
+    if isinstance(api_payload, list):
+        return _message_chars(api_payload) // 4
+
+    if isinstance(api_payload, dict):
+        messages = api_payload.get("messages")
+        if isinstance(messages, list):
+            total_chars = _message_chars(messages)
+            if "tools" in api_payload:
+                total_chars += _chars(api_payload.get("tools"))
+            return total_chars // 4
+
+        if "input" in api_payload:
+            total_chars = (
+                _chars(api_payload.get("input"))
+                + _chars(api_payload.get("instructions"))
+                + _chars(api_payload.get("tools"))
+            )
+            return total_chars // 4
+
+        return sum(_chars(value) for value in api_payload.values()) // 4
+
+    return _chars(api_payload) // 4
+
+
 
 def interruptible_api_call(agent, api_kwargs: dict):
     """
@@ -200,9 +253,7 @@ def interruptible_api_call(agent, api_kwargs: dict):
     # httpx timeout (default 1800s) with zero feedback.  The stale
     # detector kills the connection early so the main retry loop can
     # apply richer recovery (credential rotation, provider fallback).
-    _stale_timeout = agent._compute_non_stream_stale_timeout(
-        api_kwargs.get("messages", [])
-    )
+    _stale_timeout = agent._compute_non_stream_stale_timeout(api_kwargs)
 
     _call_start = time.time()
     agent._touch_activity("waiting for non-streaming API response")
@@ -226,7 +277,7 @@ def interruptible_api_call(agent, api_kwargs: dict):
         # arrives within the configured timeout.
         _elapsed = time.time() - _call_start
         if _elapsed > _stale_timeout:
-            _est_ctx = sum(len(str(v)) for v in api_kwargs.get("messages", [])) // 4
+            _est_ctx = estimate_request_context_tokens(api_kwargs)
             logger.warning(
                 "Non-streaming API call stale for %.0fs (threshold %.0fs). "
                 "model=%s context=~%s tokens. Killing connection.",
@@ -362,6 +413,7 @@ def build_api_kwargs(agent, api_messages: list) -> dict:
             reasoning_config=agent.reasoning_config,
             session_id=getattr(agent, "session_id", None),
             max_tokens=agent.max_tokens,
+            timeout=agent._resolved_api_call_timeout(),
             request_overrides=agent.request_overrides,
             is_github_responses=is_github_responses,
             is_codex_backend=is_codex_backend,
@@ -2019,7 +2071,7 @@ def interruptible_streaming_api_call(agent, api_kwargs: dict, *, on_first_delta=
         # when the context is large.  Without this, the stale detector kills
         # healthy connections during the model's thinking phase, producing
         # spurious RemoteProtocolError ("peer closed connection").
-        _est_tokens = sum(len(str(v)) for v in api_kwargs.get("messages", [])) // 4
+        _est_tokens = estimate_request_context_tokens(api_kwargs)
         if _est_tokens > 100_000:
             _stream_stale_timeout = max(_stream_stale_timeout_base, 300.0)
         elif _est_tokens > 50_000:
@@ -2055,7 +2107,7 @@ def interruptible_streaming_api_call(agent, api_kwargs: dict, *, on_first_delta=
         # inner retry loop can start a fresh connection.
         _stale_elapsed = time.time() - last_chunk_time["t"]
         if _stale_elapsed > _stream_stale_timeout:
-            _est_ctx = sum(len(str(v)) for v in api_kwargs.get("messages", [])) // 4
+            _est_ctx = estimate_request_context_tokens(api_kwargs)
             logger.warning(
                 "Stream stale for %.0fs (threshold %.0fs) — no chunks received. "
                 "model=%s context=~%s tokens. Killing connection.",