Collapses indirection layers and one-caller abstractions across the video
player, shortcut dispatch, shader loading and context-menu code, including
the VideoPIPManager pass-through over PipService.
Introduces shared seams for paginated views, D-pad reorder, media control
routing, async singletons and the device method channel, then points the
open-coded copies at them.
Also removes unused models and duplicated provider/server plumbing, folds
the twice-implemented artifact store in the server, and factors the
repeated Flutter toolchain prologue in CI into a composite action.
edde746