Cello C4 interaction sound
Original performer credited by the sample collection: flcellogrl (Freesound, real-cello-notes pack 12408).
Collection: Nicholaus P. Brosowsky, tonejs-instruments.
Source: https://github.com/nbrosowsky/tonejs-instruments/blob/master/samples/cello/C4.wav
Attribution record: https://github.com/nbrosowsky/tonejs-instruments/blob/master/sample-source-info.txt
Sample license: Creative Commons Attribution 3.0 https://creativecommons.org/licenses/by/3.0/
License declaration: https://github.com/nbrosowsky/tonejs-instruments/blob/master/LICENSE.md
Changes for this app: cropped to the first 0.65 seconds, peak-normalized to 0.75; playback uses an amplitude envelope and transposition for ascending stars.

Bibao dialogue: original procedural character syllables synthesized locally by bibao-language.mjs. No game audio or voice recordings are used. The cello sample above is used for ascending star rewards.