fix(mcp): change reasoning.effort from 'minimal' to 'low' in factory

The actual hardcoded 'minimal' value was in factories.py line 136,
not in graphiti-core's DEFAULT_REASONING constant. The factory
explicitly passes reasoning='minimal' when creating OpenAIClient
for reasoning models, overriding any default.

'minimal' is not supported by gpt-5.4-mini and newer models.
Supported values: 'none', 'low', 'medium', 'high', 'xhigh'.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: daniel-rudaev

mcp_server/src/services/factories.py

@@ -133,7 +133,7 @@ def create(config: LLMConfig) -> LLMClient:
 
                 # Only pass reasoning/verbosity parameters for reasoning models (gpt-5 family)
                 if is_reasoning_model:
-                    return OpenAIClient(config=llm_config, reasoning='minimal', verbosity='low')
+                    return OpenAIClient(config=llm_config, reasoning='low', verbosity='low')
                 else:
                     # For non-reasoning models, explicitly pass None to disable these parameters
                     return OpenAIClient(config=llm_config, reasoning=None, verbosity=None)