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.
- Correct history/resume next-previous context and list index resync after reload
- Abort stale RadioBrowser requests and suppress error banners when cache satisfies loads
- Reset local search filter on page changes and debounce compact-mode API search
- Move system tray to C++ (QSystemTrayIcon) for reliable Wayland context menus
- Harden MPRIS registration and metadata updates for Plasma media widgets
- Add playback and API race unit tests
- Drop unused KF6 Kirigami, I18n, and CoreAddons build dependencies
- Update packaging docs, CI, and PKGBUILD to match Qt-only requirements
