feat: add Chinese localization and source-language transcription

[jiezhengj]

Summary

• add automatic UI locale detection and runtime English / Simplified Chinese switching across the web and Electron surfaces
• add configurable transcription task and source language, defaulting to transcription with automatic language detection so Chinese audio remains Chinese
• persist desktop window position, dimensions, and maximized state without resizing during project transitions
• package the required offline runtime assets and add focused localization, transcription-option, and Electron window tests

Validation

• npm run lint
• npm run test:localization
• npx tsc --noEmit
• npm run typecheck:electron
• npm run dist

[vercel]

@jiezhengj is attempting to deploy a commit to the wassgha's projects Team on Vercel.

A member of the Team first needs to authorize it.

[wassgha]

Hey @jiezhengj these are awesome additions! Thank for the contribution!! However, is it possible to split the PR into the four logical tasks that you describe in the PR description? That would make it a lot easier to review 🙏🏻

[jiezhengj]

Thanks @wassgha — I split the original PR into four focused, independently based PRs as requested:

• feat(i18n): add English and Chinese UI localization #81 — UI locale detection and English / Simplified Chinese localization
• feat(transcription): preserve the detected source language #82 — source-language detection and transcription without translation
• feat(desktop): persist window bounds across launches #83 — desktop window size and position persistence
• build: refresh runtime assets before builds #84 — deterministic runtime-asset refresh before builds and exports

The relevant tests and validation notes are included with each PR. The Vercel status on fork PRs still points to upstream-team authorization, which I cannot grant from the fork account.

Closing #80 in favor of these four smaller PRs. Thanks again for the review guidance!

[wassgha]

You're awesome!