feat: add mobile cache clearing

[codedogQBY]

Summary

• Add a Storage section on the mobile Me page with a Clear Cache action
• Clear Expo runtime cache recursively after stopping TTS playback and preview audio
• Add localized clear-cache copy for zh, zh-TW, en, ja, ko, fr, and es

Fixes #276

Test

• pnpm exec biome check packages/app-expo/src/screens/ProfileScreen.tsx packages/app-expo/src/lib/platform/mobile-cache.ts packages/core/src/i18n/locales/en/profile.json packages/core/src/i18n/locales/zh/profile.json packages/core/src/i18n/locales/zh-TW/profile.json packages/core/src/i18n/locales/ja/profile.json packages/core/src/i18n/locales/ko/profile.json packages/core/src/i18n/locales/fr/profile.json packages/core/src/i18n/locales/es/profile.json
• pnpm --filter @readany/app-expo exec tsc --noEmit
• git diff --check

Note: pnpm --filter @readany/app-expo lint still fails on existing ios/Pods podspec formatting diagnostics unrelated to this change.