fix(#417): a lost take returns to the ex-taker's book, one trade row per order

lib/features/order/providers/trade_state_provider.dart

@@ -70,6 +70,11 @@ final releaseOrderActionProvider = Provider<Future<void> Function(String)>(
   (ref) => (orderId) => orders_api.releaseOrder(orderId: orderId),
 );
 
+/// Publishes a cancel for the order; the daemon's answer arrives later.
+final cancelOrderActionProvider = Provider<Future<void> Function(String)>(
+  (ref) => (orderId) => orders_api.cancelOrder(orderId: orderId),
+);
+
 /// Live order status for a single trade, polled from the order book every 2 s.
 ///
 /// Starts with an immediate fetch (no initial delay) so the first emission

lib/features/order/screens/add_lightning_invoice_screen.dart

@@ -106,7 +106,9 @@ class _AddLightningInvoiceScreenState
       builder:
           (ctx) => AlertDialog(
             title: Text(l10n.cancelTradeDialogTitle),
-            content: Text(l10n.cancelTradeDialogContent),
+            // This screen only exists before the trade goes active, where
+            // mostrod cancels at once — no cooperative request.
+            content: Text(l10n.cancelTradeDialogContentNotStarted),
             actions: [
               TextButton(
                 onPressed: () => Navigator.pop(ctx, false),

lib/features/order/screens/my_order_screen.dart

@@ -20,7 +20,6 @@ import 'package:mostro/features/order/widgets/order_detail_cards.dart';
 import 'package:mostro/features/trades/providers/trades_providers.dart';
 import 'package:mostro/l10n/app_localizations.dart';
 import 'package:mostro/shared/utils/fiat_currencies.dart';
-import 'package:mostro/src/rust/api/orders.dart' as orders_api;
 
 /// Detail screen for an order created by the current user (handoff 6a/6b).
 ///
@@ -54,8 +53,11 @@ class _MyOrderScreenState extends ConsumerState<MyOrderScreen> {
 
     setState(() => _cancelling = true);
     try {
-      await orders_api.cancelOrder(orderId: widget.orderId);
-      // Force the trades list to reload from DB so the Canceled status shows.
+      await ref.read(cancelOrderActionProvider)(widget.orderId);
+      // Reload the trades list now. A pending order never went active, so
+      // the row is not marked Canceled locally: the daemon's Canceled or its
+      // public `canceled`, whichever lands first, wipes it, and the
+      // TradeUpdate that follows reloads the list again.
       ref.invalidate(rawTradesProvider);
       if (!mounted) return;
       showOrderDetailSnackBar(

lib/features/order/screens/pay_lightning_invoice_screen.dart

@@ -67,7 +67,9 @@ class _PayLightningInvoiceScreenState
       builder:
           (ctx) => AlertDialog(
             title: Text(l10n.cancelTradeDialogTitle),
-            content: Text(l10n.cancelTradeDialogContent),
+            // This screen only exists before the trade goes active, where
+            // mostrod cancels at once — no cooperative request.
+            content: Text(l10n.cancelTradeDialogContentNotStarted),
             actions: [
               TextButton(
                 onPressed: () => Navigator.pop(ctx, false),

lib/features/trades/screens/trade_detail_screen.dart

@@ -138,14 +138,79 @@ class _TradeDetailScreenState extends ConsumerState<TradeDetailScreen> {
 
   // ── Actions ──────────────────────────────────────────────────────────────
 
-  Future<void> _cancelOrder() async {
+  /// Set once the screen has decided to leave, so no rebuild in between
+  /// navigates twice.
+  bool _leaving = false;
+
+  /// Back to home with [message], at most once.
+  void _leave(String message) {
+    if (_leaving || !mounted) return;
+    _leaving = true;
+    ScaffoldMessenger.of(
+      context,
+    ).showSnackBar(SnackBar(content: Text(message)));
+    context.go(AppRoute.home);
+  }
+
+  /// Whether a cancel in [status] ends the trade outright. Mirrors Rust's
+  /// `cancellation_wipes_history`: before `active` mostrod cancels at once —
+  /// a take hands the order back to the book, a maker's order dies — and the
+  /// trade row is wiped. From `active` on it is a cooperative request, and
+  /// `inProgress` may be either. Kept equal to the Rust predicate by
+  /// `the_trade_screen_copy_of_cancellation_wipes_history_matches`
+  /// (`rust/src/mostro/status.rs`), which reads this set from source: keep
+  /// the `=> const {…}.contains(status)` shape.
+  static bool _cancelEndsTrade(TradeStatus status) => const {
+    TradeStatus.pending,
+    TradeStatus.waitingInvoice,
+    TradeStatus.waitingPayment,
+  }.contains(status);
+
+  /// What a cancel in [status] does, as the confirmation dialog tells it.
+  /// Before `active` mostrod cancels at once; from `active` on it is a
+  /// cooperative request; `inProgress` only says the order was taken, so it
+  /// may be either (#203).
+  static String _cancelDialogContent(
+    AppLocalizations l10n,
+    TradeStatus status,
+  ) {
+    if (_cancelEndsTrade(status)) {
+      return l10n.cancelTradeDialogContentNotStarted;
+    }
+    if (status == TradeStatus.inProgress) {
+      return l10n.cancelTradeDialogContentMaybeStarted;
+    }
+    return l10n.cancelTradeDialogContent;
+  }
+
+  /// The trade's status now, from the live provider; [fallback] while it has
+  /// no value yet. The status a callback was built with goes stale across an
+  /// await: the seller's payment can land while the cancel dialog is open.
+  TradeStatus _liveStatus(TradeStatus fallback) {
+    final live = ref.read(tradeStatusProvider(widget.orderId)).valueOrNull;
+    return live == null ? fallback : tradeStatusFromOrderStatus(live);
+  }
+
+  Future<void> _cancelOrder(TradeStatus status) async {
     final l10n = AppLocalizations.of(context);
     final confirmed = await showDialog<bool>(
       context: context,
       builder:
           (ctx) => AlertDialog(
             title: Text(l10n.cancelTradeDialogTitle),
-            content: Text(l10n.cancelTradeDialogContent),
+            // Follows the live status, so the copy the user confirms is the
+            // cancel the daemon will apply.
+            content: Consumer(
+              builder: (context, dialogRef, child) {
+                final live =
+                    dialogRef
+                        .watch(tradeStatusProvider(widget.orderId))
+                        .valueOrNull;
+                final now =
+                    live == null ? status : tradeStatusFromOrderStatus(live);
+                return Text(_cancelDialogContent(l10n, now));
+              },
+            ),
             actions: [
               TextButton(
                 onPressed: () => Navigator.pop(ctx, false),
@@ -163,9 +228,17 @@ class _TradeDetailScreenState extends ConsumerState<TradeDetailScreen> {
       throw const MostroActionAborted();
     }
     try {
-      await orders_api.cancelOrder(orderId: widget.orderId);
+      await ref.read(cancelOrderActionProvider)(widget.orderId);
       ref.invalidate(rawTradesProvider);
       if (!mounted) return;
+      // Decided on the status the cancel was sent in, not the one the button
+      // was built with: a trade that went active meanwhile is a cooperative
+      // request and stays open.
+      if (_cancelEndsTrade(_liveStatus(status))) {
+        // Nothing is left to follow here: leave, as the invoice screens do.
+        _leave(l10n.cancelRequestSent);
+        return;
+      }
       ScaffoldMessenger.of(
         context,
       ).showSnackBar(SnackBar(content: Text(l10n.cancelRequestSent)));
@@ -394,14 +467,36 @@ class _TradeDetailScreenState extends ConsumerState<TradeDetailScreen> {
     // Counterpart reputation snapshot persisted from the daemon's follow-up
     // Peer DM (#305), via tradeInfoProvider: it refreshes on the TradeUpdate
     // the Rust side emits after persisting the snapshot.
-    final trade = ref.watch(tradeInfoProvider(widget.orderId)).valueOrNull;
+    final tradeAsync = ref.watch(tradeInfoProvider(widget.orderId));
+    final trade = tradeAsync.valueOrNull;
     final peerRating = trade?.peerRating;
     final room =
         ref
             .watch(chatRoomsNotifierProvider)
             .where((r) => r.orderId == widget.orderId)
             .firstOrNull;
 
+    // No trade row and not the maker: this is no longer a trade of this
+    // user's. A take lost before going active (its own cancel, a waiting
+    // timeout, the maker cancelling) is wiped in Rust, and the order is
+    // handed back to the public book, where it reads `pending` — which this
+    // screen would render as the user's own published order, cancel button
+    // included. Leave instead, as the invoice screens do; this also covers
+    // arriving later from a notification or the chat header. Only on settled
+    // reads of both the trades list and the order book: no answer yet is
+    // neither an absent row nor a stranger's order (a cold start can resolve
+    // the trades before the book's first emission).
+    if (!_leaving &&
+        ref.watch(orderBookProvider).hasValue &&
+        !tradeAsync.isLoading &&
+        tradeAsync.hasValue &&
+        trade == null &&
+        order?.isMine != true) {
+      WidgetsBinding.instance.addPostFrameCallback(
+        (_) => _leave(l10n.tradeNoLongerYours),
+      );
+    }
+
     return Scaffold(
       backgroundColor: book.bg,
       appBar: AppBar(
@@ -829,7 +924,7 @@ class _TradeDetailScreenState extends ConsumerState<TradeDetailScreen> {
             label:
                 view.cancelIsFullWidth ? l10n.cancelTradeButton : l10n.cancel,
             automationId: AutomationIds.tradeCancel,
-            onPressed: _cancelOrder,
+            onPressed: () => _cancelOrder(status),
             isDestructive: true,
           ),
           TradeSecondaryAction.dispute => TradeSecondarySpec(

lib/l10n/app_de.arb

@@ -237,6 +237,8 @@
   "backupRitualSecondFailureMessage": "Das war erneut falsch. Bitte überprüfe und sichere deine geheimen Wörter und verifiziere dann von vorne.",
   "cancelTradeDialogTitle": "Handel abbrechen?",
   "cancelTradeDialogContent": "Kooperativen Abbruch angefragt. Die andere Partei muss ebenfalls zustimmen, damit der Handel vollständig abgebrochen wird.",
+  "cancelTradeDialogContentNotStarted": "Der Handel hat noch nicht begonnen und wird daher sofort abgebrochen. Die andere Partei muss nicht zustimmen.",
+  "cancelTradeDialogContentMaybeStarted": "Hat der Handel noch nicht begonnen, wird er sofort abgebrochen. Hat er bereits begonnen, muss die andere Partei ebenfalls zustimmen.",
   "noButtonLabel": "Nein",
   "yesButtonLabel": "Ja",
   "yesCancelButtonLabel": "Ja, abbrechen",
@@ -377,6 +379,7 @@
   "payWithLightningWallet": "Mit Lightning-Wallet bezahlen",
   "noLightningWalletFound": "Keine Lightning-Wallet auf diesem Gerät gefunden",
   "orderNoLongerActive": "Diese Bestellung ist nicht mehr aktiv",
+  "tradeNoLongerYours": "Du bist nicht mehr an diesem Handel beteiligt",
   "sessionTimeoutMessage": "Keine Antwort erhalten; prüfe deine Verbindung und versuche es später erneut",
   "noIdentityFoundMessage": "Keine Identität gefunden — versuche, die App neu zu starten.",
   "failedToLoadSecretWordsMessage": "Geheime Wörter konnten nicht geladen werden. Bitte versuche es erneut.",

lib/l10n/app_en.arb

@@ -1055,7 +1055,15 @@
   },
   "cancelTradeDialogContent": "Requesting a cooperative cancel. The other party must also agree for the trade to be fully cancelled.",
   "@cancelTradeDialogContent": {
-    "description": "Body text for the cancel-trade confirmation dialog"
+    "description": "Body text for the cancel-trade confirmation dialog once the trade is active: the cancel is a cooperative request"
+  },
+  "cancelTradeDialogContentNotStarted": "The trade has not started yet, so it is cancelled right away. The other party does not need to agree.",
+  "@cancelTradeDialogContentNotStarted": {
+    "description": "Body text for the cancel-trade confirmation dialog before the trade is active (pending, waiting for the invoice or the hold-invoice payment): the daemon cancels at once"
+  },
+  "cancelTradeDialogContentMaybeStarted": "If the trade has not started yet, it is cancelled right away. If it has, the other party must also agree.",
+  "@cancelTradeDialogContentMaybeStarted": {
+    "description": "Body text for the cancel-trade confirmation dialog while the order is only known to be taken (in progress): the trade may or may not be active yet"
   },
   "noButtonLabel": "No",
   "yesButtonLabel": "Yes",
@@ -1620,7 +1628,11 @@
   },
   "orderNoLongerActive": "This order is no longer active",
   "@orderNoLongerActive": {
-    "description": "Neutral notice shown when the order reaches a terminal state (canceled, cooperatively canceled, canceled by admin, or expired) while the user is on the pay invoice screen"
+    "description": "Neutral notice shown when the order reaches a terminal state (canceled, cooperatively canceled, canceled by admin, or expired) while the user is on the add-invoice or pay-invoice screen"
+  },
+  "tradeNoLongerYours": "You're no longer part of this trade",
+  "@tradeNoLongerYours": {
+    "description": "Notice when the trade screen closes because the user no longer has a trade on this order: a take lost before it went active (their own cancel, a waiting timeout, the maker cancelling), or a later visit to such a trade from a notification. Neutral on purpose: the order may be back in the book or gone for good"
   },
   "sessionTimeoutMessage": "No response received, check your connection and try again later",
   "@sessionTimeoutMessage": {

lib/l10n/app_es.arb

@@ -237,6 +237,8 @@
   "backupRitualSecondFailureMessage": "Eso fue incorrecto de nuevo. Por favor revisa y respalda tus palabras secretas, luego verifica desde el principio.",
   "cancelTradeDialogTitle": "¿Cancelar intercambio?",
   "cancelTradeDialogContent": "Se solicita una cancelación cooperativa. La otra parte también debe aceptar para que el intercambio quede cancelado.",
+  "cancelTradeDialogContentNotStarted": "El intercambio aún no ha comenzado, así que se cancela de inmediato. No hace falta que la otra parte lo acepte.",
+  "cancelTradeDialogContentMaybeStarted": "Si el intercambio aún no ha comenzado, se cancela de inmediato. Si ya comenzó, la otra parte también debe aceptar.",
   "noButtonLabel": "No",
   "yesButtonLabel": "Sí",
   "yesCancelButtonLabel": "Sí, cancelar",
@@ -377,6 +379,7 @@
   "payWithLightningWallet": "Pagar con wallet Lightning",
   "noLightningWalletFound": "No se encontró una wallet Lightning en este dispositivo",
   "orderNoLongerActive": "Esta orden ya no está activa",
+  "tradeNoLongerYours": "Ya no participas en este intercambio",
   "sessionTimeoutMessage": "No hubo respuesta, verifica tu conexión e inténtalo más tarde",
   "noIdentityFoundMessage": "No se encontró ninguna identidad — intenta reiniciar la app.",
   "failedToLoadSecretWordsMessage": "No se pudieron cargar las palabras secretas. Inténtalo de nuevo.",

lib/l10n/app_fr.arb

@@ -237,6 +237,8 @@
   "backupRitualSecondFailureMessage": "C'est encore incorrect. Veuillez vérifier et sauvegarder vos mots secrets, puis recommencer la vérification depuis le début.",
   "cancelTradeDialogTitle": "Annuler l'échange ?",
   "cancelTradeDialogContent": "Annulation coopérative demandée. L'autre partie doit également accepter pour que l'échange soit entièrement annulé.",
+  "cancelTradeDialogContentNotStarted": "L'échange n'a pas encore commencé, il est donc annulé immédiatement. L'autre partie n'a pas besoin d'accepter.",
+  "cancelTradeDialogContentMaybeStarted": "Si l'échange n'a pas encore commencé, il est annulé immédiatement. S'il a déjà commencé, l'autre partie doit également accepter.",
   "noButtonLabel": "Non",
   "yesButtonLabel": "Oui",
   "yesCancelButtonLabel": "Oui, annuler",
@@ -377,6 +379,7 @@
   "payWithLightningWallet": "Payer avec un portefeuille Lightning",
   "noLightningWalletFound": "Aucun portefeuille Lightning trouvé sur cet appareil",
   "orderNoLongerActive": "Cet ordre n'est plus actif",
+  "tradeNoLongerYours": "Vous ne participez plus à cet échange",
   "sessionTimeoutMessage": "Aucune réponse reçue, vérifiez votre connexion et réessayez plus tard",
   "noIdentityFoundMessage": "Aucune identité trouvée — essayez de redémarrer l'application.",
   "failedToLoadSecretWordsMessage": "Échec du chargement des mots secrets. Veuillez réessayer.",

lib/l10n/app_it.arb

@@ -237,6 +237,8 @@
   "backupRitualSecondFailureMessage": "Di nuovo errato. Per favore controlla e salva le tue parole segrete, poi verifica dall'inizio.",
   "cancelTradeDialogTitle": "Annullare lo scambio?",
   "cancelTradeDialogContent": "Annullamento cooperativo richiesto. Anche l'altra parte deve accettare affinché lo scambio venga annullato.",
+  "cancelTradeDialogContentNotStarted": "Lo scambio non è ancora iniziato, quindi viene annullato subito. Non serve che l'altra parte accetti.",
+  "cancelTradeDialogContentMaybeStarted": "Se lo scambio non è ancora iniziato, viene annullato subito. Se è già iniziato, anche l'altra parte deve accettare.",
   "noButtonLabel": "No",
   "yesButtonLabel": "Sì",
   "yesCancelButtonLabel": "Sì, annulla",
@@ -377,6 +379,7 @@
   "payWithLightningWallet": "Paga con wallet Lightning",
   "noLightningWalletFound": "Nessun wallet Lightning trovato su questo dispositivo",
   "orderNoLongerActive": "Questo ordine non è più attivo",
+  "tradeNoLongerYours": "Non partecipi più a questo scambio",
   "sessionTimeoutMessage": "Nessuna risposta ricevuta, verifica la tua connessione e riprova più tardi",
   "noIdentityFoundMessage": "Nessuna identità trovata — prova a riavviare l'app.",
   "failedToLoadSecretWordsMessage": "Impossibile caricare le parole segrete. Riprova.",