feat: improve model input fields for HuggingFace model component (#5723)

* feat: improve model input fields for huggingface component

1. Make model_id, inference_endpoint and api_token fields required
2. Convert temperature to SliderInput with range 0-2
3. Update temperature info to match HuggingFace's description

Co-authored-by: Vinícios Batista da Silva <vinicios.batsi@gmail.com>

* feat(huggingface): update model selection and temperature input

This commit enhances the HuggingFace component by implementing a fixed list of
large language models in the dropdown selection and improving the temperature
input with a slider control.

Key changes in src/backend/base/langflow/components/models/huggingface.py:
- Add DEFAULT_MODEL constant set to "meta-llama/Llama-3.3-70B-Instruct"
- Replace model_id StrInput with DropdownInput containing pre-selected models:
  * meta-llama/Llama-3.3-70B-Instruct (default)
  * mistralai/Mixtral-8x7B-Instruct-v0.1
  * mistralai/Mistral-7B-Instruct-v0.3
  * meta-llama/Llama-3.1-8B-Instruct
  * Qwen/Qwen2.5-Coder-32B-Instruct
  * Qwen/QwQ-32B-Preview
  * openai-community/gpt2
  * custom option
- Add real_time_refresh to model_id dropdown for dynamic updates
- Implement custom model input field that shows/hides based on selection
- Replace temperature FloatInput with SliderInput for better UX:
  * Added RangeSpec with min=0, max=2, step=0.01
  * Maintains default value of 0.8
- Add build_config update logic to handle custom model visibility
- Update API URL generation to support custom model IDs
- Import RangeSpec and SliderInput from langflow packages

Co-authored-by: Vinícios Batista da Silva <vinicios.batsi@gmail.com>

* [autofix.ci] apply automated fixes

* test(huggingface): update tests for enhanced model selection and UI controls

This commit updates the test suite to verify the new features and changes in
the HuggingFace component, ensuring proper functionality of the model selection
dropdown and improved temperature control.

Key changes in src/backend/tests/unit/components/models/test_huggingface.py:
- Update test_huggingface_inputs to verify new DropdownInput for model_id:
  * Check DEFAULT_MODEL as default value
  * Verify presence of 'custom' option
  * Validate required and real_time_refresh settings
- Add verification for custom_model field:
  * Confirm initial custom_model hidden state
  * Verify required flag
- Add specific checks for temperature SliderInput:
  * Validate default value of 0.8
  * Verify RangeSpec configuration (min=0, max=2, step=0.01)
- Improve test structure with detailed assertions for field configurations
- Update imports to include DEFAULT_MODEL constant

Related to previous commit that enhanced the HuggingFace component with
fixed model list and slider controls.

Co-authored-by: Vinícios Batista da Silva <vinicios.batsi@gmail.com>

---------

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

src/backend/tests/unit/components/models/test_huggingface.py

@@ -1,5 +1,5 @@
-from langflow.components.models.huggingface import HuggingFaceEndpointsComponent
-from langflow.inputs.inputs import DictInput, DropdownInput, FloatInput, IntInput, SecretStrInput, StrInput
+from langflow.components.models.huggingface import DEFAULT_MODEL, HuggingFaceEndpointsComponent
+from langflow.inputs.inputs import DictInput, DropdownInput, FloatInput, IntInput, SecretStrInput, SliderInput, StrInput
 
 
 def test_huggingface_inputs():
@@ -8,12 +8,13 @@ def test_huggingface_inputs():
 
     # Define expected input types and their names
     expected_inputs = {
-        "model_id": StrInput,
+        "model_id": DropdownInput,
+        "custom_model": StrInput,
         "max_new_tokens": IntInput,
         "top_k": IntInput,
         "top_p": FloatInput,
         "typical_p": FloatInput,
-        "temperature": FloatInput,
+        "temperature": SliderInput,
         "repetition_penalty": FloatInput,
         "inference_endpoint": StrInput,
         "task": DropdownInput,
@@ -22,8 +23,24 @@ def test_huggingface_inputs():
         "retry_attempts": IntInput,
     }
 
-    # Check if all expected inputs are present
+    # Check if all expected inputs are present and have correct type
     for name, input_type in expected_inputs.items():
-        assert any(isinstance(inp, input_type) and inp.name == name for inp in inputs), (
-            f"Missing or incorrect input: {name}"
-        )
+        matching_inputs = [inp for inp in inputs if isinstance(inp, input_type) and inp.name == name]
+        assert matching_inputs, f"Missing or incorrect input: {name}"
+
+        if name == "model_id":
+            input_field = matching_inputs[0]
+            assert input_field.value == DEFAULT_MODEL
+            assert "custom" in input_field.options
+            assert input_field.required is True
+            assert input_field.real_time_refresh is True
+        elif name == "custom_model":
+            input_field = matching_inputs[0]
+            assert input_field.show is False
+            assert input_field.required is True
+        elif name == "temperature":
+            input_field = matching_inputs[0]
+            assert input_field.value == 0.8
+            assert input_field.range_spec.min == 0
+            assert input_field.range_spec.max == 2
+            assert input_field.range_spec.step == 0.01