feat(streaming): buffer resilience and automatic reconnection

- Construct the audio player with an enlarged live-stream buffer (15-50s forward cushion, 2.5s to start, 5s after rebuffer) so short network drops play through silently
- Add reconnect-on-stall state machine with bounded exponential backoff (1/2/4/8/16s, ~90s total window, 5 attempts) that re-prepares to the live edge; backoff/decision logic extracted to controlador_reconexion.dart as pure testable code
- Surface a new reconnecting playback state in the mini player and full player (localized in all 13 locales) instead of error dialogs during the retry window; a single friendly error appears only after exhaustion
- Guard interplay: user pause/stop cancels retries, audio interruptions cancel reconnect, alarm wake-up path keeps precedence, recording fails cleanly during drops
- Reset retry budget on station change; route stream timeouts through the network-error class
- 10 new tests (99 total green), flutter analyze clean

lib/l10n/app_ar.arb

@@ -477,6 +477,7 @@
   "playbackStatusConnecting": "جارٍ الاتصال...",
   "playbackStatusLive": "مباشر",
   "playbackStatusPaused": "متوقف مؤقتًا",
+  "playbackStatusReconnecting": "جارٍ إعادة الاتصال...",
   "playbackStatusConnectionError": "خطأ في الاتصال",
   "playbackStatusStopped": "متوقف",
   "stationSemanticLabel": "محطة {stationName}",

lib/l10n/app_bn.arb

@@ -477,6 +477,7 @@
   "playbackStatusConnecting": "সংযুক্ত হচ্ছে...",
   "playbackStatusLive": "লাইভ",
   "playbackStatusPaused": "বিরতিতে",
+  "playbackStatusReconnecting": "পুনরায় সংযোগ করা হচ্ছে...",
   "playbackStatusConnectionError": "সংযোগে ত্রুটি",
   "playbackStatusStopped": "বন্ধ",
   "stationSemanticLabel": "স্টেশন {stationName}",

lib/l10n/app_de.arb

@@ -477,6 +477,7 @@
   "playbackStatusConnecting": "Verbindung wird hergestellt...",
   "playbackStatusLive": "Live",
   "playbackStatusPaused": "Pausiert",
+  "playbackStatusReconnecting": "Wird neu verbunden...",
   "playbackStatusConnectionError": "Verbindungsfehler",
   "playbackStatusStopped": "Gestoppt",
   "stationSemanticLabel": "Sender {stationName}",

lib/l10n/app_en.arb

@@ -477,6 +477,7 @@
   "playbackStatusConnecting": "Connecting...",
   "playbackStatusLive": "Live",
   "playbackStatusPaused": "Paused",
+  "playbackStatusReconnecting": "Reconnecting...",
   "playbackStatusConnectionError": "Connection error",
   "playbackStatusStopped": "Stopped",
   "stationSemanticLabel": "Station {stationName}",

lib/l10n/app_es.arb

@@ -473,6 +473,7 @@
   "playbackStatusConnecting": "Conectando...",
   "playbackStatusLive": "En directo",
   "playbackStatusPaused": "Pausado",
+  "playbackStatusReconnecting": "Reconectando...",
   "playbackStatusConnectionError": "Error de conexión",
   "playbackStatusStopped": "Detenido",
   "stationSemanticLabel": "Emisora {stationName}",

lib/l10n/app_fr.arb

@@ -477,6 +477,7 @@
   "playbackStatusConnecting": "Connexion...",
   "playbackStatusLive": "En direct",
   "playbackStatusPaused": "En pause",
+  "playbackStatusReconnecting": "Reconnexion...",
   "playbackStatusConnectionError": "Erreur de connexion",
   "playbackStatusStopped": "Arrêté",
   "stationSemanticLabel": "Station {stationName}",

lib/l10n/app_hi.arb

@@ -477,6 +477,7 @@
   "playbackStatusConnecting": "कनेक्ट हो रहा है...",
   "playbackStatusLive": "लाइव",
   "playbackStatusPaused": "विराम पर",
+  "playbackStatusReconnecting": "पुनः कनेक्ट हो रहा है...",
   "playbackStatusConnectionError": "कनेक्शन त्रुटि",
   "playbackStatusStopped": "बंद",
   "stationSemanticLabel": "स्टेशन {stationName}",

lib/l10n/app_id.arb

@@ -477,6 +477,7 @@
   "playbackStatusConnecting": "Menghubungkan...",
   "playbackStatusLive": "Siaran langsung",
   "playbackStatusPaused": "Dijeda",
+  "playbackStatusReconnecting": "Menyambung ulang...",
   "playbackStatusConnectionError": "Kesalahan koneksi",
   "playbackStatusStopped": "Dihentikan",
   "stationSemanticLabel": "Stasiun {stationName}",

lib/l10n/app_it.arb

@@ -477,6 +477,7 @@
   "playbackStatusConnecting": "Connessione...",
   "playbackStatusLive": "In diretta",
   "playbackStatusPaused": "In pausa",
+  "playbackStatusReconnecting": "Riconnessione...",
   "playbackStatusConnectionError": "Errore di connessione",
   "playbackStatusStopped": "Interrotto",
   "stationSemanticLabel": "Stazione {stationName}",

lib/l10n/app_ja.arb

@@ -477,6 +477,7 @@
   "playbackStatusConnecting": "接続中...",
   "playbackStatusLive": "ライブ",
   "playbackStatusPaused": "一時停止中",
+  "playbackStatusReconnecting": "再接続中...",
   "playbackStatusConnectionError": "接続エラー",
   "playbackStatusStopped": "停止中",
   "stationSemanticLabel": "ラジオ局 {stationName}",

lib/l10n/app_pt.arb

@@ -477,6 +477,7 @@
   "playbackStatusConnecting": "Conectando...",
   "playbackStatusLive": "Ao vivo",
   "playbackStatusPaused": "Pausado",
+  "playbackStatusReconnecting": "Reconectando...",
   "playbackStatusConnectionError": "Erro de conexão",
   "playbackStatusStopped": "Parado",
   "stationSemanticLabel": "Estação {stationName}",

lib/l10n/app_ru.arb

@@ -477,6 +477,7 @@
   "playbackStatusConnecting": "Подключение...",
   "playbackStatusLive": "В эфире",
   "playbackStatusPaused": "Приостановлено",
+  "playbackStatusReconnecting": "Переподключение...",
   "playbackStatusConnectionError": "Ошибка подключения",
   "playbackStatusStopped": "Остановлено",
   "stationSemanticLabel": "Станция {stationName}",

lib/l10n/app_zh.arb

@@ -477,6 +477,7 @@
   "playbackStatusConnecting": "正在连接...",
   "playbackStatusLive": "直播中",
   "playbackStatusPaused": "已暂停",
+  "playbackStatusReconnecting": "正在重新连接...",
   "playbackStatusConnectionError": "连接错误",
   "playbackStatusStopped": "已停止",
   "stationSemanticLabel": "电台 {stationName}",

lib/l10n/gen/app_localizations.dart

@@ -1730,6 +1730,12 @@ abstract class AppLocalizations {
   /// **'Pausado'**
   String get playbackStatusPaused;
 
+  /// No description provided for @playbackStatusReconnecting.
+  ///
+  /// In es, this message translates to:
+  /// **'Reconectando...'**
+  String get playbackStatusReconnecting;
+
   /// No description provided for @playbackStatusConnectionError.
   ///
   /// In es, this message translates to:

lib/l10n/gen/app_localizations_ar.dart

@@ -919,6 +919,9 @@ class AppLocalizationsAr extends AppLocalizations {
   @override
   String get playbackStatusPaused => 'متوقف مؤقتًا';
 
+  @override
+  String get playbackStatusReconnecting => 'جارٍ إعادة الاتصال...';
+
   @override
   String get playbackStatusConnectionError => 'خطأ في الاتصال';
 

lib/l10n/gen/app_localizations_bn.dart

@@ -928,6 +928,9 @@ class AppLocalizationsBn extends AppLocalizations {
   @override
   String get playbackStatusPaused => 'বিরতিতে';
 
+  @override
+  String get playbackStatusReconnecting => 'পুনরায় সংযোগ করা হচ্ছে...';
+
   @override
   String get playbackStatusConnectionError => 'সংযোগে ত্রুটি';
 

lib/l10n/gen/app_localizations_de.dart

@@ -930,6 +930,9 @@ class AppLocalizationsDe extends AppLocalizations {
   @override
   String get playbackStatusPaused => 'Pausiert';
 
+  @override
+  String get playbackStatusReconnecting => 'Wird neu verbunden...';
+
   @override
   String get playbackStatusConnectionError => 'Verbindungsfehler';
 

lib/l10n/gen/app_localizations_en.dart

@@ -923,6 +923,9 @@ class AppLocalizationsEn extends AppLocalizations {
   @override
   String get playbackStatusPaused => 'Paused';
 
+  @override
+  String get playbackStatusReconnecting => 'Reconnecting...';
+
   @override
   String get playbackStatusConnectionError => 'Connection error';
 

lib/l10n/gen/app_localizations_es.dart

@@ -927,6 +927,9 @@ class AppLocalizationsEs extends AppLocalizations {
   @override
   String get playbackStatusPaused => 'Pausado';
 
+  @override
+  String get playbackStatusReconnecting => 'Reconectando...';
+
   @override
   String get playbackStatusConnectionError => 'Error de conexión';
 

lib/l10n/gen/app_localizations_fr.dart

@@ -933,6 +933,9 @@ class AppLocalizationsFr extends AppLocalizations {
   @override
   String get playbackStatusPaused => 'En pause';
 
+  @override
+  String get playbackStatusReconnecting => 'Reconnexion...';
+
   @override
   String get playbackStatusConnectionError => 'Erreur de connexion';
 

lib/l10n/gen/app_localizations_hi.dart

@@ -924,6 +924,9 @@ class AppLocalizationsHi extends AppLocalizations {
   @override
   String get playbackStatusPaused => 'विराम पर';
 
+  @override
+  String get playbackStatusReconnecting => 'पुनः कनेक्ट हो रहा है...';
+
   @override
   String get playbackStatusConnectionError => 'कनेक्शन त्रुटि';
 

lib/l10n/gen/app_localizations_id.dart

@@ -928,6 +928,9 @@ class AppLocalizationsId extends AppLocalizations {
   @override
   String get playbackStatusPaused => 'Dijeda';
 
+  @override
+  String get playbackStatusReconnecting => 'Menyambung ulang...';
+
   @override
   String get playbackStatusConnectionError => 'Kesalahan koneksi';
 

lib/l10n/gen/app_localizations_it.dart

@@ -930,6 +930,9 @@ class AppLocalizationsIt extends AppLocalizations {
   @override
   String get playbackStatusPaused => 'In pausa';
 
+  @override
+  String get playbackStatusReconnecting => 'Riconnessione...';
+
   @override
   String get playbackStatusConnectionError => 'Errore di connessione';
 

lib/l10n/gen/app_localizations_ja.dart

@@ -895,6 +895,9 @@ class AppLocalizationsJa extends AppLocalizations {
   @override
   String get playbackStatusPaused => '一時停止中';
 
+  @override
+  String get playbackStatusReconnecting => '再接続中...';
+
   @override
   String get playbackStatusConnectionError => '接続エラー';
 

lib/l10n/gen/app_localizations_pt.dart

@@ -925,6 +925,9 @@ class AppLocalizationsPt extends AppLocalizations {
   @override
   String get playbackStatusPaused => 'Pausado';
 
+  @override
+  String get playbackStatusReconnecting => 'Reconectando...';
+
   @override
   String get playbackStatusConnectionError => 'Erro de conexão';
 

lib/l10n/gen/app_localizations_ru.dart

@@ -929,6 +929,9 @@ class AppLocalizationsRu extends AppLocalizations {
   @override
   String get playbackStatusPaused => 'Приостановлено';
 
+  @override
+  String get playbackStatusReconnecting => 'Переподключение...';
+
   @override
   String get playbackStatusConnectionError => 'Ошибка подключения';
 

lib/l10n/gen/app_localizations_zh.dart

@@ -891,6 +891,9 @@ class AppLocalizationsZh extends AppLocalizations {
   @override
   String get playbackStatusPaused => '已暂停';
 
+  @override
+  String get playbackStatusReconnecting => '正在重新连接...';
+
   @override
   String get playbackStatusConnectionError => '连接错误';