Update alphaear skills to use MiniMax as default LLM

Changes:
- Added 'minimax' provider to LLM factory
- Changed default LLM_PROVIDER from 'ust' to 'minimax'
- Changed default LLM_MODEL from 'Qwen' to 'MiniMax-Text-01'
- Updated REASONING_MODEL_PROVIDER and TOOL_MODEL_PROVIDER to minimax
- Sentiment tools now prefer MINIMAX_API_KEY over UST_KEY_API
- .env.example updated with MiniMax defaults

.env.example

@@ -106,19 +106,19 @@ SHODH_USER_ID=default
 # JINA API - For content extraction
 JINA_API_KEY=
 
-# LLM Configuration (AlphaEar uses multiple providers)
-LLM_PROVIDER=ust
-LLM_MODEL=Qwen
+# LLM Configuration (AlphaEar uses MiniMax by default - OpenAI compatible)
+LLM_PROVIDER=minimax
+LLM_MODEL=MiniMax-Text-01
 LLM_HOST=
 
 # Reasoning Model (for alphaear-predictor)
-REASONING_MODEL_PROVIDER=openai
-REASONING_MODEL_ID=gpt-4o
+REASONING_MODEL_PROVIDER=minimax
+REASONING_MODEL_ID=MiniMax-Text-01
 REASONING_MODEL_HOST=
 
 # Tool Model (for alphaear-predictor)
-TOOL_MODEL_PROVIDER=openai
-TOOL_MODEL_ID=gpt-4o
+TOOL_MODEL_PROVIDER=minimax
+TOOL_MODEL_ID=MiniMax-Text-01
 TOOL_MODEL_HOST=
 
 # Embedding Model (for Kronos predictor)