Write a complete YouTube video script about {{topic}} for {{target_audience}} using a {{tone}} tone. Follow a three-act narrative structure with a hook within 5 seconds, pattern interrupts, and engagement cues every 90 seconds. Include pre-production notes, hook, introduction, main content (4-6 segments), climax, conclusion with CTA, and YouTube optimization (titles, description, tags, thumbnail). Keep script under 1000 words. Ensure financial claims are accurate. Include engagement cues in each section.