Match the tolerant list predicate the import path already uses. The platform
preference cache returns List<Object?> after a restart, so the exact
List<String> pattern silently dropped tracker library filter ids and a
restored profile resumed scrobbling libraries the user had excluded.
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