feat(llm): add the GPT-5.6 family and GLM-5.3

- GPT-5.6 (sol/terra/luna) is GA and OpenAI's recommended default; add it and
  make gpt-5.6 (deep) / gpt-5.6-luna (quick) the defaults
- add GLM-5.3 and GLM-5.3-Flash, Zhipu's current flagship line

tests/test_env_overrides.py

@@ -21,8 +21,8 @@ def _reload_with_env(monkeypatch, **overrides):
 def test_no_env_uses_built_in_defaults(monkeypatch):
     dc = _reload_with_env(monkeypatch)
     assert dc.DEFAULT_CONFIG["llm_provider"] == "openai"
-    assert dc.DEFAULT_CONFIG["deep_think_llm"] == "gpt-5.5"
+    assert dc.DEFAULT_CONFIG["deep_think_llm"] == "gpt-5.6"
-    assert dc.DEFAULT_CONFIG["quick_think_llm"] == "gpt-5.4-mini"
+    assert dc.DEFAULT_CONFIG["quick_think_llm"] == "gpt-5.6-luna"
     assert dc.DEFAULT_CONFIG["backend_url"] is None
     assert dc.DEFAULT_CONFIG["max_debate_rounds"] == 1
     assert dc.DEFAULT_CONFIG["checkpoint_enabled"] is False

tradingagents/default_config.py

@@ -80,8 +80,8 @@ DEFAULT_CONFIG = _apply_env_overrides({
     "memory_log_max_entries": None,
     # LLM settings
     "llm_provider": "openai",
-    "deep_think_llm": "gpt-5.5",
+    "deep_think_llm": "gpt-5.6",
-    "quick_think_llm": "gpt-5.4-mini",
+    "quick_think_llm": "gpt-5.6-luna",
     # When None, each provider's client falls back to its own default endpoint
     # (api.openai.com for OpenAI, generativelanguage.googleapis.com for Gemini, ...).
     # The CLI overrides this per provider when the user picks one. Keeping a

tradingagents/llm_clients/model_catalog.py

@@ -18,15 +18,15 @@ _CUSTOM_ONLY: dict[str, list[ModelOption]] = {
 # All GLM 4.7+ entries support thinking mode via thinking={"type":"enabled"}.
 _GLM_MODELS: dict[str, list[ModelOption]] = {
     "quick": [
+        ("GLM-5.3-Flash - Fast, cost-efficient, 1M ctx", "glm-5.3-flash"),
         ("GLM-5-Turbo - Fast, switchable thinking modes", "glm-5-turbo"),
-        ("GLM-4.7 - Previous-gen flagship", "glm-4.7"),
         ("GLM-4.5-Air - Lightweight, cost-efficient", "glm-4.5-air"),
         ("Custom model ID", "custom"),
     ],
     "deep": [
-        ("GLM-5.2 - Latest flagship, 1M ctx", "glm-5.2"),
+        ("GLM-5.3 - Latest flagship, 1M ctx", "glm-5.3"),
+        ("GLM-5.2 - 744B, 1M ctx", "glm-5.2"),
         ("GLM-5.1 - 745B, 200K ctx", "glm-5.1"),
-        ("GLM-5 - Flagship, 204K ctx", "glm-5"),
         ("GLM-4.7 - Previous-gen flagship", "glm-4.7"),
         ("Custom model ID", "custom"),
     ],
@@ -81,15 +81,15 @@ _MINIMAX_MODELS: dict[str, list[ModelOption]] = {
 MODEL_OPTIONS: ProviderModeOptions = {
     "openai": {
         "quick": [
+            ("GPT-5.6 Luna - Fast, cost-efficient frontier", "gpt-5.6-luna"),
+            ("GPT-5.6 Terra - Balances intelligence and cost", "gpt-5.6-terra"),
             ("GPT-5.4 Mini - Fast, strong coding and tool use", "gpt-5.4-mini"),
-            ("GPT-5.4 Nano - Cheapest, high-volume tasks", "gpt-5.4-nano"),
-            ("GPT-5.5 - Latest frontier, 1M context", "gpt-5.5"),
         ],
         "deep": [
-            ("GPT-5.5 - Latest frontier, 1M context", "gpt-5.5"),
+            ("GPT-5.6 - Latest frontier reasoning (Sol)", "gpt-5.6"),
-            ("GPT-5.4 - Previous-gen frontier, 1M context, cost-effective", "gpt-5.4"),
+            ("GPT-5.6 Terra - Balances intelligence and cost", "gpt-5.6-terra"),
-            ("GPT-5.2 - Strong reasoning, cost-effective", "gpt-5.2"),
+            ("GPT-5.5 - Previous-gen frontier, 1M context", "gpt-5.5"),
-            ("GPT-5.5 Pro - Most capable, expensive ($30/$180 per 1M tokens)", "gpt-5.5-pro"),
+            ("GPT-5.4 - Cost-effective, 1M context", "gpt-5.4"),
         ],
     },
     "anthropic": {