ACTIVATE whenever writing or modifying TypeScript code in src/. ACTIVATE for code review, formatting, or 'coding standards'. Provides TS-specific code style examples for the cross-language rules defined in craft:code-style-principles, plus TS-specific patterns (optional chaining, nullish coalescing, template literals, no truthy/falsy). DO NOT use for: TypeScript typing rules (see ts-conventions), test conventions, domain/infra layer boundaries (see ts-layer-boundaries).
