Relocate the pure session mutators (refresh_local_renderer_id,
is_peer/local_renderer_active, find_unique_renderer_id,
normalize_active_renderer_id, renderer_allows_remote_volume) and the
QconnectFileAudioQualitySnapshot type into qconnect-app::session.
refresh_local_renderer_id now takes an injected LocalIdentity (device
uuid + device-info) so qconnect-app stays free of the persistence /
transport crates (ADR-006). A thin Tauri wrapper resolves the identity
from default_qconnect_device_info() and delegates, keeping the three
event_sink call sites and the existing tests unchanged. The eager
device-info build is idempotent and side-effect-free, so renderer-id
resolution is byte-identical.
qconnect-app + src-tauri qconnect tests green (33 / 42).
cc