Step 7 of the renderer-engine extraction. Moves report_file/device_audio_
quality_if_changed (dedup-against-last-reported + build RendererReport + send)
out of the Tauri service into QconnectApp methods, so the Slint report-back loop
reuses them. The Tauri service methods are now thin delegates that extract
runtime.app and forward.
Byte-identical: runtime.sync_state and the Arc passed to QconnectApp::new (the
one sync_handle() returns) are clones of the SAME Mutex (service.rs:232/242/277),
so the dedup state and the report build/send are unchanged; only the owner of
the code moved. send_renderer_report_command + the last_reported_* fields were
already in qconnect-app.
Verified: cargo check -p qbz-nix clean (no warnings); qbz-nix qconnect 42/42 +
qconnect-app 38/38 green.
cc
vicrodh
a2d0df8b30