feat(settings): adjustable opacity for the favorite gold outline + star

Adds a "Favorite Highlight Opacity" slider (15-100%, default 100%) to
Settings > Appearance > Scale & Effects. It scales the alpha of the four
favorite gold tokens (fill/border/icon/outline) at their resolve site in
the Balance address list via material::ScaleAlpha, so the gold row outline
and the star button fade together. The multiplier is skin-agnostic (it
scales whatever alpha the theme resolved) and touches only favorited rows;
non-favorite rows and the white selection highlight are unchanged, and the
100% default is byte-identical to the previous look.

The preference lives in Settings (favorite_opacity, clamped 0.15-1.0 in both
the setter and on load), persists across restarts, updates live, and is not
low-spec gated (it's a pure color-alpha preference, independent of the
transparency sliders). New i18n keys favorite_opacity / tt_favorite_opacity
are translated into all eight locales; the CJK subset font is rebuilt to add
the two new glyphs the zh string needs.

Verified: full + lite builds clean, full + lite test suites pass, hygiene OK.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

res/lang/es.json

@@ -863,6 +863,7 @@
     "faq_w_set_4_q": "¿Cómo muestro precios en moneda fiat?",
     "faq_w_set_title": "Ajustes y apariencia",
     "favorite_address": "Marcar como favorito",
+    "favorite_opacity": "Opacidad del resaltado de favoritos",
     "fee": "Comisión",
     "fee_high": "Alta",
     "fee_label": "Comisión:",
@@ -2069,6 +2070,7 @@
     "tt_export_all": "Exportar todas las claves privadas a un archivo",
     "tt_export_csv": "Exportar historial de transacciones como hoja de cálculo CSV",
     "tt_export_key": "Exportar la clave privada de la dirección seleccionada",
+    "tt_favorite_opacity": "Opacidad del botón de estrella de favoritos y su contorno dorado en la lista de direcciones (mínimo 15 %)",
     "tt_fetch_prices": "Obtener precios de mercado de DRGX desde la API de CoinGecko",
     "tt_font_scale": "Escalar todo el texto y la interfaz (1.0x = predeterminado, hasta 1.5x).",
     "tt_idle_delay": "Cuánto tiempo esperar antes de empezar a minar",