fix(eq): seed device ID at startup and add device management UI

Fix multi-device EQ auto-switching by calling obtenerDispositivoActual()
during cargarPersistido() to seed the initial device ID. Add device
management modal with rename support, EQ preset editing, and connection
status indicator. Translate device UI keys to all 13 locales.

lib/l10n/gen/app_localizations_ja.dart

@@ -1214,4 +1214,24 @@ class AppLocalizationsJa extends AppLocalizations {
   String advancedEqDevicePresetLabel(Object presetName) {
     return 'プリセット: $presetName';
   }
+
+  @override
+  String preNoticeCountdown(int minutes) {
+    return '$minutes分後に開始';
+  }
+
+  @override
+  String get eqDeviceEditTitle => 'デバイスを編集';
+
+  @override
+  String get eqDeviceNameLabel => 'デバイス名';
+
+  @override
+  String get eqDeviceNameHint => '例：リビングのスピーカー';
+
+  @override
+  String get eqDeviceNameConfirm => '保存';
+
+  @override
+  String get eqDeviceConnected => '接続中';
 }