Powerful AI for expense reviews

New AI functionality for expense automation including:

• High-risk expense flagging: AI flags specific items like "vodka" even when general categories like "alcohol" aren't on the receipt
• AI-powered commenting: Brex AI assistant explains why an expense is out of policy
• Smart filtering on search: Natural language search to filter expenses by criteria (e.g., "marketing expenses > $200 without receipts last month")

These LLM-powered features make expense reviews faster and smarter.