MPRIS set_volume returning True was causing an early return that
silently skipped the PulseAudio stream write. PA-only apps like
Brave and Vesktop (registered as Chromium/electron) never had their
volume updated when any MPRIS player coincidentally matched the
target name by substring.
Both set_app_volume and reapply_app_volumes now always apply the PA
correction regardless of MPRIS result, so PA-only and MPRIS-capable
apps are handled correctly in all cases.