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_zh.dart

@@ -1207,4 +1207,24 @@ class AppLocalizationsZh extends AppLocalizations {
   String advancedEqDevicePresetLabel(Object presetName) {
     return '预设：$presetName';
   }
+
+  @override
+  String preNoticeCountdown(int minutes) {
+    return '$minutes分钟后开始';
+  }
+
+  @override
+  String get eqDeviceEditTitle => '编辑设备';
+
+  @override
+  String get eqDeviceNameLabel => '设备名称';
+
+  @override
+  String get eqDeviceNameHint => '例：客厅音箱';
+
+  @override
+  String get eqDeviceNameConfirm => '保存';
+
+  @override
+  String get eqDeviceConnected => '已连接';
 }