- Clap detection moved from inline buttons to a Tools menu, plain labels
(no more '(whole file)' / '(from cursor)' parentheticals) -- status
messages moved to the window's status bar since the dedicated label
widget went away with the button row.
- ClickableSlider subclass: clicking anywhere along the seek track jumps
straight there instead of QSlider's default page-by-a-step behavior;
reposition-then-delegate-to-super keeps native drag behavior intact.
- Dragging now seeks live via sliderMoved instead of waiting for
sliderReleased.
- PlayerWidget accepts drag-and-drop of a local file to load it.
Verified with real Qt events (QMouseEvent clicks, a QDropEvent, a real
mouse click via xdotool opening the Tools menu on an actual running
window) rather than just calling the underlying methods directly.