Pass app version and build id explicitly from Main.qml to AboutDialog
instead of relying on context properties inside the QML module scope.
Remove the confusing "Public beta" label.
Make Flatpak updates unmistakable after clients were stuck on the
May 1.0.3 commit. Expose bearwaveVersion/bearwaveBuildId to QML and
set the flatpak manifest version explicitly.
Validate manual stream URLs (http/https only), restrict notification
cover downloads to HTTPS, and add transfer timeouts for metadata and
cover fetches. Document playback, tray, MPRIS, and QML refactor changes
in CHANGELOG and AppStream metadata.
