fix(language-select): hide raw language code from translate selector trigger - #21993

…trigger (CherryHQ#21993)

### What this PR does

Before this PR:

- The translate target-language selector (`LanguageSelect` with
`searchPlacement="trigger"`) showed the raw language code in front of
the flag and localized name while closed, e.g. `zh-cn 🇨🇳 简体中文` or `ja-jp
🇯🇳 日文`.
- In trigger-search mode the closed combobox renders an `<input>` whose
value is `selectedOption.label`
(`packages/ui/src/components/primitives/combobox.tsx`), and
`LanguageSelect` built that `label` from `searchText` (code + flag +
name). The `renderValue` prop (flag + name only) applies solely to the
button trigger, so it never took effect here.

After this PR:

- Each language option carries a display `label` of flag + localized
name (`🇨🇳 简体中文`), matching the dropdown options and the `renderValue`
output.
- The code-bearing string remains in `searchText`, and `filterOption`
still matches against `searchText` and the option value, so typing a
language code (e.g. `zh-cn`) still finds the language.

Fixes CherryHQ#21967

### Why we need it and why it was done in this way

The following tradeoffs were made:

- The display label is a plain string (`flag + name`) because the
trigger-search input can only render a string value; the rich JSX
rendering (`content`) continues to be used inside the dropdown and by
`renderValue`.
- Only language options changed. `extraOptionsBefore/After` already
build their label from the plain display text with no code prefix, so
they were left untouched.

The following alternatives were considered:

- Changing the shared `Combobox` to use `renderValue` for the closed
trigger input. That would alter a shared primitive used across the app
and would also need a string fallback for the input, for a bug that is
specific to how `LanguageSelect` constructs its labels. Keeping the
change in `LanguageSelect` is the smaller, lower-risk fix.

Links to places where the discussion took place: CherryHQ#21967 (root cause and
fix direction identified there).

### Agent Note / Spec

Agent Note: N/A — one-line, localized UI bug fix on an existing
component; the issue already located the exact cause and direction, no
Spec needed.

Spec PR: N/A

Acceptance criteria: N/A — direct bug fix; verified by the two
regression cases noted below (closed selector shows flag + name only;
code search still works).

### Verification

- Environment: Node v24.22.0, pnpm 12.6.0 (corepack), Windows 11
(10.0.26200), AMD64.
- Baseline before changes: `pnpm test:renderer
src/renderer/components/__tests__/LanguageSelect.test.tsx` → 1 pass, 0
fail.
- `pnpm test:renderer
src/renderer/components/__tests__/LanguageSelect.test.tsx
src/renderer/windows/quickAssistant/translate/__tests__/TranslateWindow.test.tsx`
→ 2 files, 6 pass, 0 fail.
- Regression check: with the one-line fix reverted, the new
closed-selector test fails (`zh-cn 🇨🇳 Chinese` received instead of `🇨🇳
Chinese`); the code-search test stays green. With the fix in place, all
3 tests pass.
- `pnpm check --group types` (selected scope: renderer, `tsc --noEmit -p
tsconfig.web.json`) → passed.
- `pnpm check --group i18n` → passed (89062 translation entries
verified; 0 unused keys; no hardcoded strings).
- `pnpm exec oxlint --deny-warnings <changed files>` → 0 warnings, 0
errors; `pnpm exec eslint <changed files>` → clean; `pnpm exec oxfmt
--check <changed files>` → correct format.
- The full local suite was not run per the repository's scoped local-PR
validation guidance; CI will run the full gate once a maintainer
approves.

### Breaking changes

None. The option `value` and `searchText` are unchanged; only the
closed-trigger display string changes.

### Special notes for your reviewer

- Diff is 1 production line plus 18 test lines
(`src/renderer/components/LanguageSelect.tsx` and its existing test
file).
- Commits include DCO `Signed-off-by`; GPG/SSH cryptographic signing is
not configured on this machine.

### Checklist

- [x] Branch: This PR targets `main`
- [x] PR: The PR description is explicit enough and will help future
contributors
- [x] Code: Write code that humans can understand and Keep it simple
- [x] Refactor: You have left the code cleaner than you found it (Boy
Scout Rule)
- [x] Upgrade: Impact of this change on upgrade flows was considered and
addressed if required
- [x] Documentation: A user-guide update was considered; this fixes a
selector display detail and adds no new setting or workflow, so no docs
update is required.
- [x] Self-review: I have reviewed my own code (e.g., via
`/gh-pr-review`, `git pr diff`, or GitHub UI) before requesting review
from others

### Release note

```release-note
Translate: the target-language selector no longer shows the raw language code (e.g. "zh-cn") before the flag and language name when closed.
```

---------

Signed-off-by: zzx04-cool <[email protected]>
Co-authored-by: zzx04-cool <[email protected]>
(cherry picked from commit dcab4fe)