Move QconnectSessionState, QconnectRendererInfo, and
QconnectSessionRendererState from the Tauri adapter into the
frontend-agnostic qconnect-app::session module, re-exporting them from
the Tauri qconnect module so all existing super:: references and the
command surface compile unchanged. Field visibility widened to pub for
cross-crate access; serialized shape is unchanged.
First step of hoisting the QConnect session/liveness layer up so both
the Tauri adapter and a future Slint adapter share one session model.
qconnect crates + src-tauri qconnect tests green.
cc
vicrodh
b6ddfc1b5f