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/pt.json

@@ -863,6 +863,7 @@
     "faq_w_set_4_q": "Como exibo preços em moeda fiduciária?",
     "faq_w_set_title": "Configurações e aparência",
     "favorite_address": "Adicionar aos favoritos",
+    "favorite_opacity": "Opacidade do destaque de favoritos",
     "fee": "Taxa",
     "fee_high": "Alta",
     "fee_label": "Taxa:",
@@ -2069,6 +2070,7 @@
     "tt_export_all": "Exportar todas as chaves privadas para um arquivo",
     "tt_export_csv": "Exportar histórico de transações como planilha CSV",
     "tt_export_key": "Exportar a chave privada do endereço selecionado",
+    "tt_favorite_opacity": "Opacidade do botão de estrela de favoritos e do seu contorno dourado na lista de endereços (mínimo 15%)",
     "tt_fetch_prices": "Obter preços de mercado DRGX da API CoinGecko",
     "tt_font_scale": "Escalar todo o texto e interface (1.0x = padrão, até 1.5x).",
     "tt_idle_delay": "Quanto tempo esperar antes de iniciar a mineração",