User flag to disable all AI processing on tickets

Description
Add a user-level flag (Disable AI processing) that fully excludes that user’s tickets from any AI usage. The user must be able to enable/disable this flag autonomously (e.g. via customer portal/profile settings).

Requirements

• No AI-generated replies for those tickets
• No sending ticket data to AI models
• Disable AI assistance for agents (suggestions, summaries, chatbot)
• Visible indicator on affected tickets
• API support

Rationale
Ensure enforceable opt-out from AI for privacy/compliance needs.