TarjetaEmisora had the only good fallback for a station with no artwork --
a deterministic pick from 4 bundled illustrations with a gradient/glyph
last resort. FilaEmisoraPlana's flat rows, the Escuchar hero, the "Tus
emisoras" grid cell, the mini player and the full player each had their
own, separate, flat primaryContainer square instead.
Extract the good fallback into PluriStationArtFallback and use it from
every one of those call sites. The selection formula (asset order,
codeUnits-sum modulo) is preserved exactly, since navegacion_auto.dart
mirrors the same formula independently for Android Auto's own drawable
rotation.
Item 23 / audit 4.3, 12.4 (t4:226-232, 616-619): Favoritos and
Grabaciones rows were full glass cards / ListTiles with two stacked
buttons and no artwork slot. Replace with flat, background-less rows
via a new shared FilaEmisoraPlana widget (square art, name+meta, a
circular play affordance) plus a bespoke Grabaciones row (44x12
placeholder art -- recordings carry no per-station favicon, so this
is a themed fallback, not invented artwork).
Favoritos keeps "Move to list" / "Remove from favorites" behind an
overflow menu (same underlying methods, unchanged) instead of two
always-visible buttons, since dropping either would be a functional
regression the prototype's own row doesn't have to solve for.
Also 12.1 (t4:610): the Grabaciones header action is folder_open, not
a generic gear.
FreeTLab