fix(llm): forward reasoning effort to GPT-6 and gate minimal thinking

- reasoning_effort was forwarded only to IDs matching gpt-5 or the o-series, so
  GPT-6 models silently dropped the configured effort; match GPT-5 and later,
  with a version boundary so unrelated IDs do not match
- Gemini Pro, 3.8+ and the -latest aliases reject thinking_level "minimal"
  with a 400; send it only to numbered Flash models before 3.8 and map it to
  "low" elsewhere, since aliases move between generations

tests/test_google_thinking_level.py

@@ -1,8 +1,8 @@
 """Gemini thinking_level forwarding (Gemini 3.x).
 
 The catalog is Gemini 3.x only, which takes the string ``thinking_level``
-directly. Pro accepts low/high; Flash also accepts minimal/medium — an
+directly. Pro, Gemini 3.8+ and the -latest aliases reject "minimal" with a 400,
-unsupported "minimal" on Pro is mapped to "low".
+so it is mapped to "low" there; numbered Flash models before 3.8 accept it.
 """
 
 from unittest import mock
@@ -35,6 +35,22 @@ def test_pro_remaps_minimal_to_low():
     assert kw["thinking_level"] == "low"  # Pro doesn't accept "minimal"
 
 
+def test_flash_38_remaps_minimal_to_low():
+    kw = _captured_kwargs("gemini-3.8-flash", thinking_level="minimal")
+    assert kw["thinking_level"] == "low"  # 3.8 Flash 400s on "minimal"
+
+
+def test_flash_38_keeps_supported_levels():
+    kw = _captured_kwargs("gemini-3.8-flash", thinking_level="high")
+    assert kw["thinking_level"] == "high"
+
+
+@pytest.mark.parametrize("alias", ["gemini-flash-latest", "gemini-pro-latest"])
+def test_latest_alias_remaps_minimal_to_low(alias):
+    # Aliases move between generations; gemini-flash-latest 400s on "minimal".
+    assert _captured_kwargs(alias, thinking_level="minimal")["thinking_level"] == "low"
+
+
 def test_pro_keeps_high():
     kw = _captured_kwargs("gemini-3.1-pro-preview", thinking_level="high")
     assert kw["thinking_level"] == "high"

tests/test_openai_reasoning_effort.py

@@ -17,9 +17,10 @@ from tradingagents.llm_clients.openai_client import (
     "model,expected",
     [
         ("gpt-5.5", True), ("gpt-5.4", True), ("gpt-5.4-mini", True),
-        ("gpt-5.5-pro", True), ("o1", True), ("o3-mini", True),
+        ("gpt-5.5-pro", True), ("gpt-6-astra", True), ("o1", True), ("o3-mini", True),
         ("gpt-4.1", False), ("gpt-4o", False), ("gpt-4o-mini", False),
-        ("gpt-3.5-turbo", False),
+        ("gpt-3.5-turbo", False), ("gpt-10", True),
+        ("gpt-5foo", False), ("gpt-60x", False), ("o3rd-party", False),
     ],
 )
 def test_supports_reasoning_effort(model, expected):

tradingagents/llm_clients/google_client.py

@@ -1,3 +1,4 @@
+import re
 from typing import Any
 
 from langchain_google_genai import ChatGoogleGenerativeAI
@@ -5,6 +6,19 @@ from langchain_google_genai import ChatGoogleGenerativeAI
 from .base_client import BaseLLMClient, normalize_content
 from .validators import validate_model
 
+_GEMINI_VERSION = re.compile(r"^gemini-(\d+)\.(\d+)")
+
+
+def _accepts_minimal_thinking(model: str) -> bool:
+    """Whether ``thinking_level="minimal"`` is accepted: numbered Flash models
+    before 3.8. Pro, 3.8+ and version-less aliases (which move between
+    generations) are treated as rejecting it."""
+    model_lc = model.lower()
+    match = _GEMINI_VERSION.match(model_lc)
+    return bool(match) and "pro" not in model_lc and (
+        (int(match.group(1)), int(match.group(2))) < (3, 8)
+    )
+
 
 class NormalizedChatGoogleGenerativeAI(ChatGoogleGenerativeAI):
     """ChatGoogleGenerativeAI with normalized content output.
@@ -42,12 +56,12 @@ class GoogleClient(BaseLLMClient):
             llm_kwargs["google_api_key"] = google_api_key
 
         # Gemini 3.x takes the string ``thinking_level`` (the integer
-        # ``thinking_budget`` was for the now-retired 2.5 line). Pro accepts
+        # ``thinking_budget`` was for the now-retired 2.5 line). Pro, Gemini
-        # low/high; Flash also accepts minimal/medium — so map an unsupported
+        # 3.8+ and the -latest aliases reject "minimal" with a 400; "low" is
-        # "minimal" on Pro to the nearest level it does accept.
+        # accepted everywhere, so it is the fallback.
         thinking_level = self.kwargs.get("thinking_level")
         if thinking_level:
-            if "pro" in self.model.lower() and thinking_level == "minimal":
+            if thinking_level == "minimal" and not _accepts_minimal_thinking(self.model):
                 thinking_level = "low"
             llm_kwargs["thinking_level"] = thinking_level
 

tradingagents/llm_clients/openai_client.py

@@ -168,11 +168,11 @@ _PASSTHROUGH_KWARGS = (
     "api_key", "callbacks", "http_client", "http_async_client",
 )
 
-# OpenAI's ``reasoning_effort`` is only accepted by reasoning models — the GPT-5
+# OpenAI's ``reasoning_effort`` is only accepted by reasoning models — GPT-5 and
-# family and the o-series. Non-reasoning models (gpt-4.1, gpt-4o, ...) 400 with
+# later, and the o-series. Non-reasoning models (gpt-4.1, gpt-4o, ...) 400 with
 # "Unsupported parameter: 'reasoning.effort' is not supported with this model".
 # Drop the kwarg for those rather than crash the run.
-_OPENAI_REASONING_MODEL = re.compile(r"^(gpt-5|o[1-9])")
+_OPENAI_REASONING_MODEL = re.compile(r"^(?:gpt-(?:[5-9]|[1-9]\d)|o[1-9])(?:[.-]|$)")
 
 
 def _supports_reasoning_effort(model: str) -> bool: