Two breaks that only appeared on a full `cargo test --workspace`.
`slint::android` exists only when compiling for Android, so darkroom-android
failed to compile on the host even though it is a workspace member. The entry
point is now gated on the target rather than on a feature.
The timeline forwarded `scrub` where the Timeline component declares
`scrub-to`, which the Slint compiler rejects.
Assisted-by: LLM
