feat: unify model selection and complete favorite settings

tests/unit/admin_console/test_model_settings.py

@@ -91,19 +91,27 @@ def test_new_install_uses_playones_endpoint_without_overriding_saved_url(monkeyp
     assert service.get_model_settings()["base_url"] == "https://saved.example/v1"
 
 
-def test_model_presets_include_flash_pro_and_luna_without_restricting_custom_names():
+def test_model_presets_keep_supported_choices_without_restricting_custom_names():
     presets = service.get_model_settings()["model_presets"]
     assert presets == [
+        "gpt-6-luna",
         "gpt-6.1-sol",
         "gpt-6-astra",
-        "gpt-5.6-luna",
-        "gpt-6-luna",
-        "mimo-v2.6-flash",
         "mimo-v2.6-pro",
     ]
     assert service.ModelSettingsUpdate(model="custom/model-v2").model == "custom/model-v2"
 
 
+def test_new_install_defaults_to_luna_high_and_preserves_saved_model(isolated_settings):
+    from artemis.config.constants import DEFAULT_MODEL
+
+    fresh = Settings(_env_file=None)
+    assert DEFAULT_MODEL == fresh.OPENAI_MODEL == "gpt-6-luna"
+    assert fresh.OPENAI_REASONING_EFFORT == "high"
+    isolated_settings.write_text("OPENAI_MODEL=custom/existing\n", encoding="utf-8")
+    assert Settings(_env_file=isolated_settings).OPENAI_MODEL == "custom/existing"
+
+
 @pytest.mark.parametrize(
     "url",
     [