Completes the renumber-safe split of THEMING.md.
- §8 "añadir componente" + §9 "definir theme" -> src/uix/eidos/THEMING_GUIDE.md
(E4 authoring guides).
- §15 "comparación con librerías" + §17 "FAQ — decisiones polémicas" ->
src/uix/eidos/THEMING_NOTES.md (E3 comparison + rationale).
THEMING.md keeps numbered pointer-stubs at §8/§9/§15/§17; §16 anti-patterns,
the ## Referencias section, and the dated §20-34 changelog stay in place. All
34 sections and every "THEMING §N" citation across the corpus + code survive.
THEMING 2571 -> 1930 lines across the three commits; it is now a leaner E1
layer reference with TSC (E2), the guides (E4) and the notes (E3) as siblings.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
