fix: use model_id without provider prefix when loading settings (#280)

* fix: use model_id without provider prefix when loading settings

When loading settings in basic mode, the model_select dropdown was being
set to the full model string (e.g., 'cerebras/zai-glm-4.6') but the
dropdown options only contain model_ids without the provider prefix
(e.g., 'zai-glm-4.6'). This caused an InvalidSelectValueError when
opening the settings screen with a previously configured model.

The fix uses the model variable (extracted from splitting llm.model by '/')
instead of the full llm.model string when setting model_select.value.

Also updated the test to reflect the correct behavior where model options
don't include the provider prefix.

Co-authored-by: openhands <openhands@all-hands.dev>

* fix: shorten long comments to pass linter

---------

Co-authored-by: openhands <openhands@all-hands.dev>

Author: neubig

openhands_cli/tui/modals/settings/settings_screen.py

@@ -174,7 +174,8 @@ def _load_current_settings(self) -> None:
 
                 # Update model options and select current model
                 self._update_model_options(provider)
-                self.model_select.value = llm.model
+                # Use model without provider prefix (dropdown options don't have it)
+                self.model_select.value = model
 
         # API Key (show masked version)
         if llm.api_key:

tests/refactor/modals/settings/test_settings_screen.py

@@ -132,9 +132,10 @@ async def test_load_current_settings_basic_mode(
     screen.current_agent = fake_agent_store.load()
 
     with patch.object(ss, "get_model_options") as mock_get_options:
+        # Model options don't include provider prefix
         mock_get_options.return_value = [
-            ("GPT-4o Mini", "openai/gpt-4o-mini"),
-            ("GPT-4o", "openai/gpt-4o"),
+            ("gpt-4o-mini", "gpt-4o-mini"),
+            ("gpt-4o", "gpt-4o"),
         ]
         screen._load_current_settings()
 
@@ -147,7 +148,8 @@ async def test_load_current_settings_basic_mode(
     assert screen.is_advanced_mode is False
     assert mode_select.value == "basic"
     assert provider_select.value == "openai"
-    assert model_select.value == "openai/gpt-4o-mini"
+    # Model select value should be model_id without provider prefix
+    assert model_select.value == "gpt-4o-mini"
 
     placeholder = api_key_input.placeholder
     assert placeholder.startswith("Current: tes")