Update LanguageSelector to display flags

[guan404ming]

Why

It would be more straightforward for users to select language with flag shown
Thanks to @eladkal 's good idea

How

• add flag property to each supportedLanguages entry
• languageSelector uses flag from supportedLanguages for display

Screen.Recording.2025-06-10.at.11.24.38.AM.mov

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[eladkal]

Nice!

[pierrejeambrun]

Sometimes it's better to use svg flags instead of emojis which can appear differently depending on the browser and often feel less formal.

But we can start with this and improve later.

[jscheffl]

Very cool!