Core Principles for React 19 SPA Development Production-ready best practices for building modern React applications with TypeScript, Vite, and TanStack ecosystem. Stack Overview - React 19 with React Compiler (auto-memoization) - TypeScript (strict mode) - Vite (bundler) - Biome (formatting + linting) - TanStack Query (server state) - TanStack Router (file-based routing) - Vitest (testing with jsdom) - Apidog MCP (API spec source of truth) Project Structure Key Principles: - One responsibility per file - UI components don't fetch server data - Put queries/mutations in feature hooks - Co-locat…