zbus features unify across the dependency graph and "tokio" wins over
"async-io": enabling it via rfd, ashpd (secret portal) and ksni's
default features flipped the shared zbus 5 executor to tokio for
accesskit_unix/atspi too — Slint's accessibility backend opens its
D-Bus connection on a plain thread and panicked at startup ("there is
no reactor running, must be called from the context of a Tokio 1.x
runtime"), killing AT-SPI support. Switch every zbus-5 consumer we
control to the async-io backend (rfd "async-std", ashpd "async-io",
ksni default-features off + "async-io"): async-io connections
self-drive from any thread and the futures still await fine inside our
tokio runtime. The zbus 4 group (keyring/secret-service/mpris-server/
qbz-audio) is a separate feature graph and stays on tokio by design.
cc
Moves the credentials module (keyring + AES-256-GCM encrypted file
store for Qobuz credentials and the OAuth token) out of src-tauri into
a new qbz-credentials crate. src-tauri/credentials re-exports it, so the
Tauri app keeps identical behavior while the Slint shell can share the
exact same implementation, encrypted file, and keyring entries.
The module was already fully self-contained (no Tauri, no crate::
references); only the dependency declarations move with it.
cc
vicrodh