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/ja.json

@@ -863,6 +863,7 @@
     "faq_w_set_4_q": "法定通貨での価格を表示するには？",
     "faq_w_set_title": "設定と外観",
     "favorite_address": "お気に入りに追加",
+    "favorite_opacity": "お気に入りハイライトの不透明度",
     "fee": "手数料",
     "fee_high": "高い",
     "fee_label": "手数料：",
@@ -2069,6 +2070,7 @@
     "tt_export_all": "すべての秘密鍵をファイルにエクスポート",
     "tt_export_csv": "トランザクション履歴を CSV スプレッドシートとしてエクスポート",
     "tt_export_key": "選択したアドレスの秘密鍵をエクスポート",
+    "tt_favorite_opacity": "アドレス一覧のお気に入りスターボタンとその金色の枠線の不透明度（最小15%）",
     "tt_fetch_prices": "CoinGecko API から DRGX の市場価格を取得",
     "tt_font_scale": "すべてのテキストと UI をスケーリング（1.0x = デフォルト、最大 1.5x）。",
     "tt_idle_delay": "マイニング開始前の待機時間",