Enable Reasoning Mode Toggle for AI Characters

Add a user-facing toggle to enable or disable Reasoning Mode for AI characters. This would allow users to control whether the model generates responses with verbose, logical, step-by-step analysis (Smart) or defaults to concise, conversational replies (Fast). The toggle should:

• Persist across sessions via character profile settings.

• Be accessible in the character configuration panel.

• Display a button on chat input, similar to web enabled.