chore: Update default OpenAI model to gpt-4o-mini

Changed the default LLM model from gpt-4o to gpt-4o-mini across all
configuration files for better cost efficiency while maintaining quality.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

mcp_server/config/config-docker-falkordb.yaml

@@ -8,7 +8,7 @@ server:
   
 llm:
   provider: "openai"  # Options: openai, azure_openai, anthropic, gemini, groq
-  model: "gpt-4o"
+  model: "gpt-4o-mini"
   temperature: 0.0
   max_tokens: 4096
   

mcp_server/config/config-docker-kuzu.yaml

@@ -9,7 +9,7 @@ server:
   
 llm:
   provider: "openai"  # Options: openai, azure_openai, anthropic, gemini, groq
-  model: "gpt-4o"
+  model: "gpt-4o-mini"
   temperature: 0.0
   max_tokens: 4096
   

mcp_server/config/config-docker-neo4j.yaml

@@ -8,7 +8,7 @@ server:
   
 llm:
   provider: "openai"  # Options: openai, azure_openai, anthropic, gemini, groq
-  model: "gpt-4o"
+  model: "gpt-4o-mini"
   temperature: 0.0
   max_tokens: 4096
   

mcp_server/config/config.yaml

@@ -8,7 +8,7 @@ server:
   
 llm:
   provider: "openai"  # Options: openai, azure_openai, anthropic, gemini, groq
-  model: "gpt-4o"
+  model: "gpt-4o-mini"
   temperature: 0.0
   max_tokens: 4096