fix: correct Ollama URL normalization and add Azure OpenAI support

- Fix bug where URL with trailing slash (e.g., http://my-ollama/v1/)
  would incorrectly become http://my-ollama/v1/v1
- Add Azure OpenAI as first-class LLM provider
- Use DRY pattern for environment variable fallbacks in AzureClient
- Address Gemini Code Assist review feedback

tradingagents/llm_clients/factory.py

@@ -5,6 +5,7 @@ from .openai_client import OpenAIClient
 from .anthropic_client import AnthropicClient
 from .google_client import GoogleClient
 from .azure_client import AzureClient
+from .azure_client import AzureClient
 
 
 def create_llm_client(