Custom AI Prompts for Transaction Categorization

Allow users to provide custom instructions (prompts) to guide how AI categorizes their transactions. This gives users control over categorization behavior based on their personal spending patterns and preferences.

Key Features:

• Add “Custom Instructions” text field in AI settings

• Users enter prompts to guide AI categorization (e.g., “Transactions from ‘Starbucks’ should be ‘Coffee’”)

• Custom prompt used in bank sync & manual import

• Only available for users with personal AI API keys

• 500 character limit with input sanitization

Requirements: Character count display, helpful placeholder examples, sanitization against prompt injection attacks.