fix(bienvenida,grabaciones): headline size, CTA radius, storage caption

Screen 14 / audit 14.3+14.7: welcome headline now 34px/ls-1.2 (was
headlineMedium's 28/ls-1.0), CTA restyled to a radius-18 rounded
rectangle instead of Material 3's default StadiumBorder (t4:696,715).

Screen 12 / audit 12.2+12.3: the recordings storage card now shows the
bold "X of Y used" headline ABOVE a 6px/radius-3 bar, followed by a
real folder-path + purge-policy caption below it -- was the bar first
with the "used" string as its only (small, generic) caption (t4:613).
New ARB key recordingsLibraryStorageFolderCaption, translated to all
13 locales.

Item 12.5 (folder/max-size settings living behind the header action
instead of inline on this screen) is a deliberate structural split
from WU15b; the audit itself scopes it out of this pass.

lib/l10n/app_zh.arb

@@ -262,8 +262,11 @@
   "searchCountryFilterLabel": "国家/地区",
   "searchLanguageFilterLabel": "语言",
   "searchMinQualityFilterLabel": "最低质量",
+  "searchLoadingStationsLabel": "正在搜索电台…",
   "searchEmptyTitle": "搜索电台",
   "searchNoResultsTitle": "没有结果",
+  "searchNoResultsForQueryTitle": "未找到与\"{query}\"相关的结果",
+  "@searchNoResultsForQueryTitle": {"placeholders": {"query": {}}},
   "searchEmptySubtitle": "使用顶部搜索栏或筛选标签，发现世界各地的电台信号。",
   "searchNoResultsSubtitle": "尝试减少筛选条件，或换个名称搜索，找到正在播出的电台。",
   "countrySpain": "西班牙",
@@ -440,6 +443,7 @@
       }
     }
   },
+  "alarmSnoozeUsualLabel": "常用",
   "saveFavoritesAlarmHint": "将电台保存到收藏，即可把它们用作音乐闹钟。",
   "useCurrentStationAction": "使用当前电台",
   "playDuringVacations": "假期期间响铃",
@@ -589,6 +593,7 @@
       "days": {}
     }
   },
+  "alarmRepeatSectionLabel": "重复",
   "androidReliabilityTitle": "检查 Android 可靠性",
   "closeAction": "关闭",
   "customOption": "自定义",
@@ -705,6 +710,7 @@
   "alarmVolumeRisingStatus": "音量渐强中",
   "countriesAllTitle": "所有国家",
   "countriesScreenTitle": "国家",
+  "countriesSearchHint": "国家或代码...",
   "countriesYourLanguagesTitle": "你的语言",
   "customStationsAddCta": "添加自定义电台",
   "equalizerActiveOutputDefault": "此设备的扬声器",
@@ -746,6 +752,7 @@
   "recordingRenameEmptyError": "请输入名称",
   "recordingRenameLabel": "名称",
   "recordingsLibraryEmptySubtitle": "你保存的录音会显示在这里。",
+  "recordingsLibraryStorageFolderCaption": "Music/PluriWave · 达到上限时会删除最旧的文件",
   "recordingsLibraryEmptyTitle": "暂无录音",
   "recordingsLibrarySettingsTooltip": "录音设置",
   "recordingsLibraryStorageCaption": "已使用 {usedMb} MB / 共 {totalMb} MB",