test(devices): cover rename surviving a re-pair cycle end to end

The rename-priority and reconnect-dedup behaviors were each tested in
isolation but never composed: connect, rename, disconnect, re-pair
with the same MAC. Adds that regression test asserting no duplicate
entry appears, the preset entry survives untouched, and the custom
name still wins after reconnection.

test/estado/estado_ecualizador_test.dart

@@ -1319,6 +1319,64 @@ void main() {
         eq.dispose();
       },
     );
+
+    test(
+      '3.10 rename persists after re-pair — composed regression '
+      '(closes bt-device-identity CRITICAL-1)',
+      () async {
+        final fakeDispositivo = FakeServicioDispositivoAudio();
+        const btDevice = DispositivoAudio(
+          id: 'bt_a2dp:AA:BB:CC:DD:EE:FF',
+          tipo: TipoDispositivo.bluetoothA2dp,
+          nombre: 'AirPods Pro',
+        );
+        const builtinSpeaker = DispositivoAudio(
+          id: 'builtin_speaker',
+          tipo: TipoDispositivo.altavozInterno,
+          nombre: 'Speaker',
+        );
+        final eq = EstadoEcualizador(
+          audio: FakeServicioAudio(),
+          servicio: FakeServicioEcualizador(eqMultiDeviceEnabled: true),
+          dispositivoAudio: fakeDispositivo,
+          emisoraActualUuid: () => stationUuid,
+        );
+        await eq.cargarPersistido();
+
+        // Connect: real-MAC id, first-seen bootstrap creates a preset entry.
+        fakeDispositivo.emitirDispositivo(btDevice);
+        await Future<void>.delayed(const Duration(milliseconds: 50));
+        final presetTrasConectar = eq.presetsDispositivo[btDevice.id];
+        expect(presetTrasConectar, isNotNull);
+
+        // Rename the device via the in-app edit dialog path.
+        await eq.renombrarDispositivo(btDevice.id, 'My Headphones');
+        expect(
+          eq.nombreVisible(btDevice.id, eq.nombrePlataforma(btDevice.id)),
+          equals('My Headphones'),
+        );
+        final cantidadTrasRenombrar = eq.presetsDispositivo.length;
+
+        // Disconnect: platform reports the transient builtin_speaker fallback.
+        fakeDispositivo.emitirDispositivo(builtinSpeaker);
+        await Future<void>.delayed(const Duration(milliseconds: 50));
+
+        // Re-pair: same physical device reconnects, reporting the SAME MAC.
+        fakeDispositivo.emitirDispositivo(btDevice);
+        await Future<void>.delayed(const Duration(milliseconds: 50));
+
+        // No duplicate entry: presetsDispositivo did not grow.
+        expect(eq.presetsDispositivo.length, equals(cantidadTrasRenombrar));
+        // The device's own preset entry survives untouched (not overwritten).
+        expect(eq.presetsDispositivo[btDevice.id], equals(presetTrasConectar));
+        // Custom rename still wins over the re-cached platform name.
+        expect(
+          eq.nombreVisible(btDevice.id, eq.nombrePlataforma(btDevice.id)),
+          equals('My Headphones'),
+        );
+        eq.dispose();
+      },
+    );
   });
 
   group('FakeServicioEcualizador — nombresDispositivos preservation (WARNING-3)', () {