feat(settings): make return-to-list-after-action configurable (default on)

Per review: gate the return-to-list behaviour behind a setting,
returnToListAfterAction, defaulting to true (the Gmail/Yahoo default). When off,
deleting the open message keeps the previous auto-advance-to-next behaviour.

Adds the setting to the store (persisted), a toggle under Reading settings, and
i18n keys across all locales (English; non-English need translation). The same
setting will govern mark-as-unread (#468).

app/(main)/[locale]/page.tsx

@@ -3101,11 +3101,13 @@ export default function Home() {
                     onForward={handleForward}
                     onDelete={() => {
                       // Deleting the open message returns to the list (Gmail-style),
-                      // not the next email. Deselect first so the store's
+                      // not the next email — unless the user turned the setting off.
-                      // remove-and-advance sees no selection and doesn't auto-open
+                      // Deselect first so the store's remove-and-advance sees no
-                      // the next message; then delete the captured email.
+                      // selection and doesn't auto-open the next message.
                       const target = selectedEmail;
+                      if (useSettingsStore.getState().returnToListAfterAction) {
                         handleMobileBack();
+                      }
                       handleDelete(target);
                     }}
                     onArchive={() => handleArchive()}

components/settings/reading-settings.tsx

@@ -22,6 +22,7 @@ export function ReadingSettings() {
     markAsReadDelay,
     deleteAction,
     permanentlyDeleteJunk,
+    returnToListAfterAction,
     showPreview,
     mailLayout,
     disableThreading,
@@ -176,6 +177,13 @@ export function ReadingSettings() {
         />
       </SettingItem>
 
+      <SettingItem label={t('return_to_list_after_action.label')} description={t('return_to_list_after_action.description')}>
+        <ToggleSwitch
+          checked={returnToListAfterAction}
+          onChange={(checked) => updateSetting('returnToListAfterAction', checked)}
+        />
+      </SettingItem>
+
       {!isSettingHidden('showPreview') && (
       <SettingItem
         label={t('show_preview.label')}

locales/cs/common.json

@@ -1226,6 +1226,10 @@
         "off": "Vypnuto",
         "seconds": "{seconds} sekund",
         "unsupported": "Aktuální účet neoznamuje podporu odloženého odeslání. Nastavení zůstane uloženo pro jiné účty."
+      },
+      "return_to_list_after_action": {
+        "label": "Return to list after delete or mark unread",
+        "description": "After deleting or marking the open message unread, go back to the message list instead of opening the next message."
       }
     },
     "composer": {

locales/da/common.json

@@ -1229,6 +1229,10 @@
         "off": "Fra",
         "seconds": "{seconds} sekunder",
         "unsupported": "Den aktuelle konto annoncerer ikke understøttelse af forsinket afsendelse. Indstillingen gemmes stadig for andre konti."
+      },
+      "return_to_list_after_action": {
+        "label": "Return to list after delete or mark unread",
+        "description": "After deleting or marking the open message unread, go back to the message list instead of opening the next message."
       }
     },
     "composer": {

locales/de/common.json

@@ -1226,6 +1226,10 @@
         "off": "Aus",
         "seconds": "{seconds} Sekunden",
         "unsupported": "Das aktuelle Konto meldet keine Unterstützung für verzögertes Senden. Die Einstellung bleibt für andere Konten gespeichert."
+      },
+      "return_to_list_after_action": {
+        "label": "Return to list after delete or mark unread",
+        "description": "After deleting or marking the open message unread, go back to the message list instead of opening the next message."
       }
     },
     "composer": {

locales/en/common.json

@@ -1229,6 +1229,10 @@
         "off": "Off",
         "seconds": "{seconds} seconds",
         "unsupported": "The current account does not advertise delayed-send support. The setting is still saved for other accounts."
+      },
+      "return_to_list_after_action": {
+        "label": "Return to list after delete or mark unread",
+        "description": "After deleting or marking the open message unread, go back to the message list instead of opening the next message."
       }
     },
     "composer": {

locales/es/common.json

@@ -1226,6 +1226,10 @@
         "off": "Desactivado",
         "seconds": "{seconds} segundos",
         "unsupported": "La cuenta actual no anuncia compatibilidad con envío demorado. La opción seguirá guardada para otras cuentas."
+      },
+      "return_to_list_after_action": {
+        "label": "Return to list after delete or mark unread",
+        "description": "After deleting or marking the open message unread, go back to the message list instead of opening the next message."
       }
     },
     "composer": {

locales/fr/common.json

@@ -1226,6 +1226,10 @@
         "off": "Désactivé",
         "seconds": "{seconds} secondes",
         "unsupported": "Le compte actuel n’annonce pas la prise en charge de l’envoi différé. Le réglage reste enregistré pour d’autres comptes."
+      },
+      "return_to_list_after_action": {
+        "label": "Return to list after delete or mark unread",
+        "description": "After deleting or marking the open message unread, go back to the message list instead of opening the next message."
       }
     },
     "composer": {

locales/hu/common.json

@@ -1229,6 +1229,10 @@
         "off": "Kikapcsolva",
         "seconds": "{seconds} másodperc",
         "unsupported": "A jelenlegi fiók nem támogatja a késleltetett küldést. A beállítás más fiókokhoz elmentésre kerül."
+      },
+      "return_to_list_after_action": {
+        "label": "Return to list after delete or mark unread",
+        "description": "After deleting or marking the open message unread, go back to the message list instead of opening the next message."
       }
     },
     "composer": {

locales/it/common.json

@@ -1226,6 +1226,10 @@
         "off": "Disattivato",
         "seconds": "{seconds} secondi",
         "unsupported": "L’account corrente non dichiara il supporto all’invio ritardato. L’impostazione resta salvata per altri account."
+      },
+      "return_to_list_after_action": {
+        "label": "Return to list after delete or mark unread",
+        "description": "After deleting or marking the open message unread, go back to the message list instead of opening the next message."
       }
     },
     "composer": {

locales/ja/common.json

@@ -1226,6 +1226,10 @@
         "off": "オフ",
         "seconds": "{seconds} 秒",
         "unsupported": "現在のアカウントは遅延送信のサポートを通知していません。この設定は他のアカウント用に保存されます。"
+      },
+      "return_to_list_after_action": {
+        "label": "Return to list after delete or mark unread",
+        "description": "After deleting or marking the open message unread, go back to the message list instead of opening the next message."
       }
     },
     "composer": {

locales/ko/common.json

@@ -1226,6 +1226,10 @@
         "off": "끔",
         "seconds": "{seconds}초",
         "unsupported": "현재 계정은 지연 보내기 지원을 알리지 않습니다. 설정은 다른 계정을 위해 계속 저장됩니다."
+      },
+      "return_to_list_after_action": {
+        "label": "Return to list after delete or mark unread",
+        "description": "After deleting or marking the open message unread, go back to the message list instead of opening the next message."
       }
     },
     "composer": {

locales/lv/common.json

@@ -1226,6 +1226,10 @@
         "off": "Izslēgts",
         "seconds": "{seconds} sekundes",
         "unsupported": "Pašreizējais konts neziņo par aizturētas sūtīšanas atbalstu. Iestatījums joprojām tiks saglabāts citiem kontiem."
+      },
+      "return_to_list_after_action": {
+        "label": "Return to list after delete or mark unread",
+        "description": "After deleting or marking the open message unread, go back to the message list instead of opening the next message."
       }
     },
     "composer": {

locales/nl/common.json

@@ -1226,6 +1226,10 @@
         "off": "Uit",
         "seconds": "{seconds} seconden",
         "unsupported": "Het huidige account meldt geen ondersteuning voor vertraagd verzenden. De instelling blijft opgeslagen voor andere accounts."
+      },
+      "return_to_list_after_action": {
+        "label": "Return to list after delete or mark unread",
+        "description": "After deleting or marking the open message unread, go back to the message list instead of opening the next message."
       }
     },
     "composer": {

locales/pl/common.json

@@ -1226,6 +1226,10 @@
         "off": "Wyłączone",
         "seconds": "{seconds} sekund",
         "unsupported": "Bieżące konto nie zgłasza obsługi opóźnionej wysyłki. Ustawienie pozostanie zapisane dla innych kont."
+      },
+      "return_to_list_after_action": {
+        "label": "Return to list after delete or mark unread",
+        "description": "After deleting or marking the open message unread, go back to the message list instead of opening the next message."
       }
     },
     "composer": {

locales/pt/common.json

@@ -1226,6 +1226,10 @@
         "off": "Desativado",
         "seconds": "{seconds} segundos",
         "unsupported": "A conta atual não anuncia suporte a envio atrasado. A configuração continuará salva para outras contas."
+      },
+      "return_to_list_after_action": {
+        "label": "Return to list after delete or mark unread",
+        "description": "After deleting or marking the open message unread, go back to the message list instead of opening the next message."
       }
     },
     "composer": {

locales/ro/common.json

@@ -1229,6 +1229,10 @@
         "off": "Oprit",
         "seconds": "{seconds} secunde",
         "unsupported": "Contul curent nu indică faptul că acceptă trimiterea amânată. Setarea este totuși salvată pentru alte conturi."
+      },
+      "return_to_list_after_action": {
+        "label": "Return to list after delete or mark unread",
+        "description": "After deleting or marking the open message unread, go back to the message list instead of opening the next message."
       }
     },
     "composer": {

locales/ru/common.json

@@ -1226,6 +1226,10 @@
         "off": "Выкл.",
         "seconds": "{seconds} сек.",
         "unsupported": "Текущая учетная запись не заявляет поддержку отложенной отправки. Настройка сохранится для других учетных записей."
+      },
+      "return_to_list_after_action": {
+        "label": "Return to list after delete or mark unread",
+        "description": "After deleting or marking the open message unread, go back to the message list instead of opening the next message."
       }
     },
     "composer": {

locales/tr/common.json

@@ -1226,6 +1226,10 @@
         "off": "Kapalı",
         "seconds": "{seconds} saniye",
         "unsupported": "Geçerli hesap gecikmeli gönderim desteği bildirmiyor. Ayar diğer hesaplar için kaydedilmeye devam eder."
+      },
+      "return_to_list_after_action": {
+        "label": "Return to list after delete or mark unread",
+        "description": "After deleting or marking the open message unread, go back to the message list instead of opening the next message."
       }
     },
     "composer": {

locales/uk/common.json

@@ -1226,6 +1226,10 @@
         "off": "Вимкнено",
         "seconds": "{seconds} с",
         "unsupported": "Поточний обліковий запис не повідомляє про підтримку відкладеного надсилання. Налаштування залишиться збереженим для інших облікових записів."
+      },
+      "return_to_list_after_action": {
+        "label": "Return to list after delete or mark unread",
+        "description": "After deleting or marking the open message unread, go back to the message list instead of opening the next message."
       }
     },
     "composer": {

locales/zh/common.json

@@ -1226,6 +1226,10 @@
         "off": "关闭",
         "seconds": "{seconds} 秒",
         "unsupported": "当前账户未声明支持延迟发送。该设置仍会为其他账户保存。"
+      },
+      "return_to_list_after_action": {
+        "label": "Return to list after delete or mark unread",
+        "description": "After deleting or marking the open message unread, go back to the message list instead of opening the next message."
       }
     },
     "composer": {

stores/settings-store.ts

@@ -137,6 +137,7 @@ interface SettingsState {
   markAsReadDelay: number; // milliseconds (0 = instant, -1 = never)
   deleteAction: DeleteAction;
   permanentlyDeleteJunk: boolean; // Permanently delete emails from junk/spam instead of moving to trash
+  returnToListAfterAction: boolean; // After delete / mark-unread in an open message, return to the list instead of opening the next message
   showPreview: boolean;
   mailLayout: MailLayout;
   emailsPerPage: number;
@@ -330,6 +331,7 @@ const DEFAULT_SETTINGS = {
   markAsReadDelay: 0, // Instant
   deleteAction: 'trash' as DeleteAction,
   permanentlyDeleteJunk: false,
+  returnToListAfterAction: true,
   showPreview: true,
   mailLayout: 'split' as MailLayout,
   emailsPerPage: 50,
@@ -533,6 +535,7 @@ export const useSettingsStore = create<SettingsState>()(
           firstDayOfWeek: state.firstDayOfWeek,
           markAsReadDelay: state.markAsReadDelay,
           deleteAction: state.deleteAction,
+          returnToListAfterAction: state.returnToListAfterAction,
           showPreview: state.showPreview,
           mailLayout: state.mailLayout,
           emailsPerPage: state.emailsPerPage,