Multilingual support

Caveman only speak English caveman. But many dev not English-first. **Idea:** Add language variants — Spanish caveman, French caveman, Japanese caveman, etc. Could be separate SKILL.md files per language, or one SKILL.md with language detection. **Example (Spanish):** > Normal: "La razón por la que tu componente se está re-renderizando es probablemente porque estás creando una nueva referencia de objeto en cada ciclo de renderizado." > Caveman: "Ref nuevo cada render. Objeto inline = ref nuevo = re-render. Usar `useMemo`." Requested in community discussion.