Change UI default LLM provider from Groq to HuggingFace

Both Test Question and Full Evaluation tabs now default to HuggingFace.

Co-Authored-By: Claude <noreply@anthropic.com>

app.py

@@ -572,7 +572,7 @@ with gr.Blocks() as demo:
                 llm_provider_dropdown = gr.Dropdown(
                     label="LLM Provider",
                     choices=["Gemini", "HuggingFace", "Groq", "Claude"],
-                    value="Groq",
+                    value="HuggingFace",
                     info="Select which LLM to use for this test",
                 )
                 enable_fallback_checkbox = gr.Checkbox(
@@ -629,7 +629,7 @@ with gr.Blocks() as demo:
                 eval_llm_provider_dropdown = gr.Dropdown(
                     label="LLM Provider for Evaluation",
                     choices=["Gemini", "HuggingFace", "Groq", "Claude"],
-                    value="Groq",
+                    value="HuggingFace",
                     info="Select which LLM to use for all questions",
                 )
                 eval_enable_fallback_checkbox = gr.Checkbox(