Drop regional suffix from Traditional Chinese label

[SnowfallC]

Summary

The Traditional Chinese option in the language picker was labeled 繁體中文（臺灣）. This drops the （臺灣） regional suffix so the label reads simply 繁體中文.

Why

Traditional Chinese is not specific to Taiwan. It is the standard written script in Hong Kong and Macau as well, and zh-Hant (the BCP-47 tag this language maps to) is script-based rather than region-based. Tying the label to a single region is misleading for users in HK/Macau. The bare 繁體中文 matches how most cross-region Chinese software labels this option (e.g. macOS, iOS, Google products).

What changed

• `rust/src/settings/types.rs`: `display_name()` returns `"繁體中文"`.
• `GeneralTab.tsx`: fallback `LanguageOption` display updated to match.
• Matching test assertions in `settings/tests.rs`, `locale_cmd.rs`, and `GeneralTab.test.tsx`.

The `value` (`"chinesetraditional"`), the `zh-tw`/`zh-hant` aliases in `parse_locale_language`, and the `.ftl` filename are all unchanged — only the user-facing label.

Verification

```
cargo test --manifest-path rust/Cargo.toml settings::tests
pnpm --dir apps/desktop-tauri test
cargo fmt --all
```

[Finesssee]

Thanks for the PR, I will review it ASAP