Implement CameraX GPG QR transfer on Android (#106)

android/README.md

@@ -8,6 +8,8 @@ UniFFI API. Local-first and HTTPS onboarding is described in
 revision-checked [adaptive navigation](../docs/android/password-navigation.md);
 Home renders Rust-owned [Git activity and HTTPS synchronization](../docs/android/home-sync.md).
 Passwords and Preferences share [Rust-owned biometric authentication](../docs/android/authentication.md).
+CameraX GPG scanning and QR export are described in
+[key transfer](../docs/android/key-transfer.md).
 Remaining feature screens retain their milestone issues. The full [CI and emulator workflow](../docs/android/ci.md) documents the
 ARM-only runner/toolchain policy and artifact audits.