fusengine

SOLID principles for React 19. Files < 100 lines, hooks separated, interfaces in src/interfaces/, JSDoc mandatory. Use for React architecture and code quality.

tvOS platform-specific development with focus system, large screen UI, Siri Remote, and media playback. Use when building Apple TV apps, video streaming, or living room experiences.

Effects utilities Tailwind CSS v4.1. Shadows (shadow-*, shadow-color, inset-shadow-* NEW), Opacity (opacity-*), Filters (blur, brightness, contrast, grayscale, sepia), Backdrop filters (backdrop-blur-*, backdrop-brightness-*), Masks (mask-* NEW).

Astro Starlight documentation theme — setup, sidebar config, Pagefind search, dark/light mode, plugins (DocSearch, blog, openapi, typedoc, versions), multi-language, Content Layer API, llms.txt, customization. Use for building documentation sites.

Phase 5: Verify contrast >= 4.5:1 text / 3:1 UI in both light+dark, check no Inter/Roboto/Arial/Open Sans, confirm all colors are OKLCH from design-system.md, validate hover/focus/disabled/loading states, run anti-AI-slop checklist.

Implement full-text search with Laravel Scout. Use when adding search to Eloquent models with Meilisearch, Algolia, or database driver.

Use when styling Astro components with scoped CSS, CSS Modules, Tailwind CSS, UnoCSS, or Sass. Covers class:list directive, global styles, CSS custom properties, and Vite-powered preprocessors.

A/B testing and performance metrics for prompts

Use when optimizing for AI search engines (Generative Engine Optimization 2026). Covers Google AI Overviews, ChatGPT, Perplexity, Claude, Gemini, Copilot, LLM-readiness scoring 0-100, llms.txt.

Testing Library for React 19 - render, screen, userEvent, waitFor, Suspense. Use when writing tests for React components with Vitest.

Use when validating code quality after modifications. Runs sniper agent in isolated forked context for clean, fast validation.

SwiftUI fundamentals for all Apple platforms. Use when building views, navigation, data persistence, or state management with SwiftUI across iOS, macOS, iPadOS, watchOS, visionOS.