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/de.json

@@ -863,6 +863,7 @@
     "faq_w_set_4_q": "Wie zeige ich Fiat-Preise an?",
     "faq_w_set_title": "Einstellungen & Erscheinungsbild",
     "favorite_address": "Als Favorit markieren",
+    "favorite_opacity": "Deckkraft der Favoriten-Hervorhebung",
     "fee": "Gebühr",
     "fee_high": "Hoch",
     "fee_label": "Gebühr:",
@@ -2069,6 +2070,7 @@
     "tt_export_all": "Alle privaten Schlüssel in eine Datei exportieren",
     "tt_export_csv": "Transaktionsverlauf als CSV-Tabelle exportieren",
     "tt_export_key": "Den privaten Schlüssel der ausgewählten Adresse exportieren",
+    "tt_favorite_opacity": "Deckkraft des Favoriten-Sterns und seiner goldenen Umrandung in der Adressliste (mindestens 15 %)",
     "tt_fetch_prices": "DRGX-Marktpreise von der CoinGecko-API abrufen",
     "tt_font_scale": "Alle Texte und UI skalieren (1.0x = Standard, bis 1.5x).",
     "tt_idle_delay": "Wie lange vor dem Start des Minings gewartet werden soll",