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.
Delete unused registry members (ProfileConnectionRegistry.insertIfAbsent /
removeAllForProfile, ProfileRegistry.reorder, ProfilesView.countFor,
ConnectionRegistry.getDefault) and their orphan tests, refreshing the stale
docs that named removeAllForProfile as the profile-delete cleanup path.
Repair the "one default per profile" join-row invariant: the connectionId FK
cascade (foreign_keys=ON) silently drops a profile's default row while its
other rows survive, leaving it defaultless. Add promoteMissingDefaults, share
a deterministic re-promotion helper with remove(), and re-promote in
removeAllForConnection.
The aired-order rework can sweep correctly-placed Specials into "download
next N"; this toggle lets users opt out. Shown only for whole shows
(reusing FocusableSwitchListTile via an optional toggle on the shared
option-picker dialog), remembered across opens via a BoolPref
(default on = unchanged behavior). Filters Specials at the single
collect choke point (_collectPlayable), with a guard so explicitly
downloading the Specials season still queues its episodes.
edde746