[Feature] Config lever for PublicKeyCredential.isUserVerifyingPlatformAuthenticatorAvailable() (uvpaa) — always false, incoherent for macOS / Windows-Hello profiles

[adamillu5t0-lab]

Summary

PublicKeyCredential.isUserVerifyingPlatformAuthenticatorAvailable() (uvpaa) always
resolves to false regardless of the spoofed OS. For fingerprint profiles that emulate
devices which overwhelmingly ship a platform authenticator — MacBooks with Touch ID, or
Windows PCs with Windows Hello — a real Firefox returns true. Camoufox returning false
is a coherence signal (reads as headless/VM/no-biometric). Requesting a config lever to
control it.

Environment

• Camoufox 152.0.4-beta.28, headless, driven via Playwright (sync API), Windows host.
• Tested on an HTTPS origin (secure context required for PublicKeyCredential).

Reproduction (HTTPS page)

await PublicKeyCredential.isUserVerifyingPlatformAuthenticatorAvailable() // → false
await PublicKeyCredential.isConditionalMediationAvailable()               // → true
navigator.platform                                                        // "MacIntel" (os="macos")  |  "Win32" (os="windows")