feat(connectivity): restyle offline and reconnect banners

Tint the mini player's reconnecting/error sub-states with the
offlineAccent token (added in WU1, unused until now): the status
label, the reconnect spinner, and the error retry icon now read as
visually distinct "connectivity trouble" states instead of blending
into the ordinary loading/paused look. Plain buffering keeps the
default colour, confirmed by a dedicated regression test.

Verify-first gate (task 16.1): ControladorReconexion.intentos exists,
but ServicioAudio never surfaces it past a debug log line, and its
estadoStream only carries the EstadoReproduccion enum. Adding an
attempt-count label would require a getter/stream on
servicio_audio.dart, one of the files this change must keep at an
empty diff against main. Ship the restyle without the counter, per
the risk register's own fallback.

WU16.

openspec/changes/rediseno-funcional/tasks.md

@@ -971,7 +971,7 @@ real capability living in the header, not decorative chrome).
 - [x] 15b.6 Verify — scoped suite green: 605/605 (up from 604), 2 skipped (unchanged, both pre-existing WU15
       documented skips). `flutter analyze`: 1 issue, identical to baseline. Literal-encoding scan: zero hits.
 
-
+## WU16 — Connectivity banner restyle (offline / reconnect)
 
 **Commit**: `feat(connectivity): restyle offline and reconnect banners`
 **Depends on**: WU1
@@ -979,16 +979,31 @@ real capability living in the header, not decorative chrome).
 **Verify**: `flutter test test/widgets/reconnect_ui_test.dart test/servicios/servicio_audio_reconnect_test.dart && flutter analyze && dart format --set-exit-if-changed $(git diff --name-only --diff-filter=ACM HEAD -- '*.dart')`
 **Modified tests**: `reconnect_ui_test.dart`. `servicio_audio_reconnect_test.dart` must pass unmodified.
 
-- [ ] 16.1 Verify-first — run `servicio_audio_reconnect_test.dart` and inspect the reconnect controller: confirm
-       whether it tracks an attempt count.
-- [ ] 16.2 RED — restyle test for the offline banner (visual only) and, **only if 16.1 confirms an attempt count
-       exists**, a test for the "Reconectando · intento N de M" label.
-- [ ] 16.3 GREEN — restyle the offline banner to the new visual language.
-- [ ] 16.4 GREEN — **conditionally**: wire the attempt-count label only if the controller exposes one; otherwise
-       ship the restyle without the counter — do not add new plumbing to invent one.
-- [ ] 16.5 REFACTOR — confirm shimmer skeletons (`TarjetaEmisoraShimmer`) are unchanged.
-- [ ] 16.6 Verify — `reconnect_ui_test.dart` updated and green; `servicio_audio_reconnect_test.dart` unmodified and
-       green.
+- [x] 16.1 Verify-first — run `servicio_audio_reconnect_test.dart` and inspect the reconnect controller: confirm
+       whether it tracks an attempt count. **Result: it does NOT reach the UI.** `ControladorReconexion.intentos`
+       exists as a getter, but `ServicioAudio` (`lib/servicios/servicio_audio.dart`) only ever reads it inside a
+       `developer.log` debug line (line 413) — its public `estadoStream` maps every playback state to the
+       `EstadoReproduccion` enum (no attempt-count payload) and `_handler.reconectando` is a bare bool. Wiring a
+       count to the UI would require adding a getter/stream to `servicio_audio.dart`, which is one of the four
+       files this change must keep at an **empty git diff vs `main`** — structurally blocked, not just untested.
+       Shipping without the counter per 16.4, exactly as the risk register anticipated.
+- [x] 16.2 RED — 3 new `testWidgets` cases added to `reconnect_ui_test.dart` (no attempt-count test, per 16.1):
+       reconnecting tints the spinner + status label with `offlineAccent`; plain `cargando` keeps the default
+       spinner colour (regression guard proving the tint is reconnect-specific, not blanket-loading); error tints
+       the retry icon + status label with `offlineAccent`. Confirmed RED: 2 of the 3 failed (`Actual: <null>`)
+       against the pre-restyle widget.
+- [x] 16.3 GREEN — `lib/widgets/mini_reproductor.dart`: the status-label `Text` and the reconnect spinner /
+       error retry icon now read `context.pluriTokens.offlineAccent` (WU1's previously-unused token, whose own
+       doc comment already named it for this WU) whenever the stream reports `reconectando` or `error`. Plain
+       `cargando` explicitly keeps `color: null` (the theme default) — verified by 16.2's regression test.
+- [x] 16.4 GREEN — conditional step confirmed moot: no attempt-count label added, no new plumbing introduced.
+- [x] 16.5 REFACTOR — `TarjetaEmisoraShimmer` (`lib/widgets/tarjeta_emisora.dart`, consumed by
+       `pantalla_buscar.dart`) is untouched by this commit — confirmed via `git diff --stat`, zero lines.
+- [x] 16.6 Verify — scoped suite green: 16/16 (5 `reconnect_ui_test.dart` + 8 `servicio_audio_reconnect_test.dart`
+       [byte-identical, unmodified] + 3 `mini_reproductor_configurar_test.dart` re-run as an adjacent-file
+       regression check). `flutter analyze`: 1 issue, identical to baseline. Scoped `dart format`: reformatted the
+       hand-written production file once (whitespace only), stable on re-run. Literal-encoding scan: zero hits on
+       the 2 touched files.
 
 ## WU17 — Welcome / onboarding screen