fix: replace paid OpenRouter models with FREE alternatives

fix: AI Assistant now generates exact block types not categories

fix: add fallback block lookup by name in NodeInspector

fix: prevent modal header from scrolling with flex-shrink-0

fix: make prepayment modal scrollable and properly centered

fix: allow minimum prepayment and add currency/autoRecharge to schema

feat: add BotFather instructions to AI Assistant response

feat: complete Section J with menu-based trading bot architecture

feat: add Section J - Menu-Based Trading Bots (simple approach)

fix: replace unicode arrows with ASCII in comments

feat: add Section J - Hybrid Trading Workflows to AI Assistant

feat: add hybrid workflow architecture to AI Assistant

feat: validate Telegram credentials in inline keyboard block

feat: auto-fix button format when LLM sends strings

fix: add button format validation to catch LLM mistakes early