feat(phase14): NWC wallet integration — connect, settings, auto-pa

lib/core/app_routes.dart

@@ -13,6 +13,8 @@ import 'package:mostro/features/chat/screens/chat_room_screen.dart';
 import 'package:mostro/features/chat/screens/chat_rooms_screen.dart';
 import 'package:mostro/features/disputes/screens/dispute_chat_screen.dart';
 import 'package:mostro/features/rate/screens/rate_counterpart_screen.dart';
+import 'package:mostro/features/settings/screens/connect_wallet_screen.dart';
+import 'package:mostro/features/settings/screens/wallet_settings_screen.dart';
 import 'package:mostro/features/trades/screens/trade_detail_screen.dart';
 import 'package:mostro/features/trades/screens/trades_screen.dart';
 import 'package:mostro/features/walkthrough/providers/first_run_provider.dart';
@@ -178,11 +180,11 @@ final GoRouter appRouter = GoRouter(
     ),
     GoRoute(
       path: AppRoute.walletSettings,
-      builder: (_, __) => const _Stub('Wallet Settings'),
+      builder: (_, __) => const WalletSettingsScreen(),
     ),
     GoRoute(
       path: AppRoute.connectWallet,
-      builder: (_, __) => const _Stub('Connect Wallet'),
+      builder: (_, __) => const ConnectWalletScreen(),
     ),
     GoRoute(
       path: AppRoute.rateUser,

lib/features/order/screens/add_lightning_invoice_screen.dart

@@ -4,6 +4,8 @@ import 'package:go_router/go_router.dart';
 
 import 'package:mostro/core/app_routes.dart';
 import 'package:mostro/core/app_theme.dart';
+import 'package:mostro/features/settings/providers/nwc_provider.dart';
+import 'package:mostro/shared/widgets/nwc_invoice_widget.dart';
 
 /// Add Lightning Invoice screen — Route `/add_invoice/:orderId`.
 ///
@@ -13,9 +15,12 @@ class AddLightningInvoiceScreen extends ConsumerStatefulWidget {
   const AddLightningInvoiceScreen({
     super.key,
     required this.orderId,
+    this.amountSats,
   });
 
   final String orderId;
+  /// Sats amount for the invoice. `null` until the trade provider resolves it.
+  final int? amountSats;
 
   @override
   ConsumerState<AddLightningInvoiceScreen> createState() =>
@@ -26,6 +31,8 @@ class _AddLightningInvoiceScreenState
     extends ConsumerState<AddLightningInvoiceScreen> {
   final _invoiceController = TextEditingController();
   bool _submitting = false;
+  /// `true` when NWC is connected but generation failed → show manual form.
+  bool _manualMode = false;
 
   @override
   void dispose() {
@@ -63,6 +70,30 @@ class _AddLightningInvoiceScreenState
     final cardBg = colors?.backgroundCard ?? const Color(0xFF1E2230);
     final inputBg = colors?.backgroundInput ?? const Color(0xFF252A3A);
 
+    final isWalletConnected = ref.watch(isWalletConnectedProvider);
+
+    // If NWC wallet is connected, amount is known, and we haven't fallen back
+    // to manual, show the auto-invoice widget instead of the manual form.
+    final sats = widget.amountSats;
+    if (isWalletConnected && !_manualMode && sats != null && sats > 0) {
+      return Scaffold(
+        appBar: AppBar(title: const Text('Add Invoice')),
+        body: Padding(
+          padding: const EdgeInsets.all(AppSpacing.lg),
+          child: Center(
+            child: NwcInvoiceWidget(
+              amountSats: sats,
+              onInvoiceConfirmed: (invoice) {
+                _invoiceController.text = invoice;
+                _submit();
+              },
+              onFallbackToManual: () => setState(() => _manualMode = true),
+            ),
+          ),
+        ),
+      );
+    }
+
     return Scaffold(
       appBar: AppBar(title: const Text('Add Invoice')),
       body: Padding(

lib/features/order/screens/pay_lightning_invoice_screen.dart

@@ -7,6 +7,8 @@ import 'package:share_plus/share_plus.dart';
 
 import 'package:mostro/core/app_routes.dart';
 import 'package:mostro/core/app_theme.dart';
+import 'package:mostro/features/settings/providers/nwc_provider.dart';
+import 'package:mostro/shared/widgets/nwc_payment_widget.dart';
 
 /// Pay Lightning Invoice screen — Route `/pay_invoice/:orderId`.
 ///
@@ -33,6 +35,8 @@ class _PayLightningInvoiceScreenState
       'jyzpnpryz4jns7qs9qyyssqjrvz0waerp2g3kx6k2neqfmfp2sxlm0n3m';
 
   bool _waiting = false;
+  /// `true` when NWC is connected but payment failed → show QR fallback.
+  bool _manualMode = false;
 
   void _simulatePaymentDetected() {
     setState(() => _waiting = true);
@@ -49,6 +53,27 @@ class _PayLightningInvoiceScreenState
     final green = colors?.mostroGreen ?? const Color(0xFF8CC63F);
     final cardBg = colors?.backgroundCard ?? const Color(0xFF1E2230);
 
+    final isWalletConnected = ref.watch(isWalletConnectedProvider);
+
+    // If NWC wallet is connected and payment hasn't failed yet, show auto-pay.
+    if (isWalletConnected && !_manualMode) {
+      return Scaffold(
+        appBar: AppBar(title: const Text('Pay Lightning Invoice')),
+        body: Padding(
+          padding: const EdgeInsets.all(AppSpacing.lg),
+          child: Center(
+            child: NwcPaymentWidget(
+              bolt11: _mockInvoice,
+              // TODO(bridge): pass real sats amount from trade provider.
+              amountSats: 0,
+              onPaymentSuccess: _simulatePaymentDetected,
+              onFallbackToManual: () => setState(() => _manualMode = true),
+            ),
+          ),
+        ),
+      );
+    }
+
     return Scaffold(
       appBar: AppBar(title: const Text('Pay Lightning Invoice')),
       body: Padding(

lib/features/settings/providers/nwc_provider.dart

@@ -0,0 +1,68 @@
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+
+// Sentinel for copyWith nullable fields.
+const _unset = Object();
+
+/// Wallet connection state held in memory.
+///
+/// `null`  → no wallet connected.
+/// non-null → wallet connected; contains pubkey + relay URLs + optional balance.
+class NwcWalletState {
+  NwcWalletState({
+    required this.walletPubkey,
+    required List<String> relayUrls,
+    this.walletName,
+    this.balanceSats,
+  }) : relayUrls = List.unmodifiable(relayUrls);
+
+  final String walletPubkey;
+  /// Immutable list of NWC relay URLs.
+  final List<String> relayUrls;
+  final String? walletName;
+  final int? balanceSats;
+
+  NwcWalletState copyWith({
+    String? walletPubkey,
+    List<String>? relayUrls,
+    String? walletName,
+    Object? balanceSats = _unset,
+  }) =>
+      NwcWalletState(
+        walletPubkey: walletPubkey ?? this.walletPubkey,
+        relayUrls: relayUrls ?? this.relayUrls,
+        walletName: walletName ?? this.walletName,
+        balanceSats: identical(balanceSats, _unset)
+            ? this.balanceSats
+            : balanceSats as int?,
+      );
+}
+
+// ── Notifier ───────────────────────────────────────────────────────────────────
+
+class NwcNotifier extends StateNotifier<NwcWalletState?> {
+  NwcNotifier() : super(null);
+
+  /// Store wallet state after a successful `connect_wallet` call.
+  void setConnected(NwcWalletState wallet) => state = wallet;
+
+  /// Clear wallet state after `disconnect_wallet`.
+  void setDisconnected() => state = null;
+
+  /// Update balance from a `get_balance` result.
+  void updateBalance(int? sats) {
+    final current = state;
+    if (current == null) return;
+    state = current.copyWith(balanceSats: sats);
+  }
+}
+
+// ── Providers ─────────────────────────────────────────────────────────────────
+
+/// Wallet connection state. `null` when no wallet is connected.
+final nwcProvider =
+    StateNotifierProvider<NwcNotifier, NwcWalletState?>((ref) => NwcNotifier());
+
+/// Convenience: `true` when a wallet is connected.
+final isWalletConnectedProvider = Provider<bool>(
+  (ref) => ref.watch(nwcProvider) != null,
+);