Chinese language support

[Denielliu]

when will the Android app support Chinese display?

[vide]

I can add It, but I literally have 0 Chinese knowledge, so I need to trust the LLM output on this. You can review the PR when it's ready though.

[vide]

Chinese language support is ready for review: #210

All 448 strings + 7 plurals translated to Simplified Chinese (简体中文). Technical terms (kW, kWh, AC, DC, etc.) are kept untranslated.

@Denielliu — since this was generated by an LLM, your review of the translations would be very appreciated! The file to review is app/src/main/res/values-zh/strings.xml.