[PM-42508] rednote "Passkeys not supported for this app"

### Origin

Native Application (non-browser app)

### Web URL or App name

https://www.xiaohongshu.com/; com.xingin.xhs

### Passkey Action

- [x] Creating new passkey (Registration)
- [ ] Signing in (Authentication)

### Build Information

© Bitwarden Inc. 2015-2026

Version: 2026.8.0 (21819)
📱 OPPO CPH2797 🤖 16@36 📦 prod
🧱 commit: bitwarden/android/release/2026.8-rc60@8be53c1ae519ab417b64b0d2154f9815adf7c44a
💻 build source: bitwarden/android/actions/runs/31214376447/attempts/1
🦀 SDK: 3.0.0-8157-eb825d59
🌩 Server: 2026.8.0 @ US

### Additional Information

Flight recorder

[bitwarden_flight_recorder3145624313105503937.zip](https://github.com/user-attachments/files/31470751/bitwarden_flight_recorder3145624313105503937.zip)

### Issue Tracking Info

- [x] I understand that work is tracked outside of Github. A PR will be linked to this issue should one be opened to address it, but Bitwarden doesn't use fields like "assigned", "milestone", or "project" to track progress.

Reproduce passkey registration for https://www.xiaohongshu.com/ (com.xingin.xhs) on the reported OPPO CPH2797 setup using Android 16 and Bitwarden 2026.8.0. Start by reviewing the attached flight recorder and the reported build details; done means identifying why registration reports “Passkeys not supported for this app” and confirming the supported registration flow works for this app.

Written by the indexing model from the issue text.