feat(block2): Ğ1 — publish a Ğ1 address + 'Pay in Ğ1' in chat (levels 1-2)

The optional Ğ1 (free currency) integration, per g1-integration.md.
- Profile: an optional 'Ğ1 address' field, persisted locally and published in
  your NIP-01 kind:0 metadata (separate from the Nostr key).
- commons_core: UserProfile/ProfileTransport carry a 'g1' field (round-trip
  tested).
- Chat: when the peer published a Ğ1 address, a 'Pay in Ğ1' app-bar action opens
  their wallet (url_launcher) so value moves in the wallet, not the app — copies
  the address as a fallback. No payment rails in-app (sharing-model §4.3).

NOTE (vjrj): the wallet deep-link uses the Cesium web wallet as a universal
fallback; swap the URI in chat_screen._payG1 for the Ğ1nkgo/Ğecko scheme you
prefer. Analyzer clean (both packages); profile transport test covers g1.

apps/app_seeds/lib/i18n/en.i18n.json

@@ -367,6 +367,8 @@
     "nameHint": "How others see you",
     "about": "About",
     "aboutHint": "A short line — what you grow, where",
+    "g1": "Ğ1 address (optional)",
+    "g1Hint": "So people can pay you in Ğ1 — separate from your key",
     "yourId": "Your identity",
     "idHelp": "Share this so people can recognise you",
     "copy": "Copy",
@@ -383,7 +385,9 @@
     "hint": "Write a message…",
     "send": "Send",
     "empty": "No messages yet — say hello",
-    "offline": "Set up sharing to send messages"
+    "offline": "Set up sharing to send messages",
+    "payG1": "Pay in Ğ1",
+    "g1Copied": "Ğ1 address copied — paste it in your wallet"
   },
   "trust": {
     "none": "No one vouches for them yet",

apps/app_seeds/lib/i18n/es.i18n.json

@@ -367,6 +367,8 @@
     "nameHint": "Cómo te ven los demás",
     "about": "Sobre ti",
     "aboutHint": "Una línea — qué cultivas, dónde",
+    "g1": "Dirección Ğ1 (opcional)",
+    "g1Hint": "Para que te paguen en Ğ1 — aparte de tu clave",
     "yourId": "Tu identidad",
     "idHelp": "Compártela para que te reconozcan",
     "copy": "Copiar",
@@ -383,7 +385,9 @@
     "hint": "Escribe un mensaje…",
     "send": "Enviar",
     "empty": "Aún no hay mensajes — saluda",
-    "offline": "Configura el compartir para enviar mensajes"
+    "offline": "Configura el compartir para enviar mensajes",
+    "payG1": "Pagar en Ğ1",
+    "g1Copied": "Dirección Ğ1 copiada — pégala en tu cartera"
   },
   "trust": {
     "none": "Nadie los avala aún",

apps/app_seeds/lib/i18n/pt.i18n.json

@@ -363,6 +363,8 @@
     "nameHint": "Como os outros te veem",
     "about": "Sobre ti",
     "aboutHint": "Uma linha — o que cultivas, onde",
+    "g1": "Endereço Ğ1 (opcional)",
+    "g1Hint": "Para que te paguem em Ğ1 — separado da tua chave",
     "yourId": "A tua identidade",
     "idHelp": "Partilha-a para que te reconheçam",
     "copy": "Copiar",
@@ -379,7 +381,9 @@
     "hint": "Escreve uma mensagem…",
     "send": "Enviar",
     "empty": "Ainda não há mensagens — diz olá",
-    "offline": "Configura a partilha para enviar mensagens"
+    "offline": "Configura a partilha para enviar mensagens",
+    "payG1": "Pagar em Ğ1",
+    "g1Copied": "Endereço Ğ1 copiado — cola-o na tua carteira"
   },
   "trust": {
     "none": "Ainda ninguém os avaliza",

apps/app_seeds/lib/i18n/strings.g.dart

@@ -4,9 +4,9 @@
 /// To regenerate, run: `dart run slang`
 ///
 /// Locales: 3
-/// Strings: 1031 (343 per locale)
+/// Strings: 1043 (347 per locale)
 ///
-/// Built on 2026-07-10 at 10:36 UTC
+/// Built on 2026-07-10 at 11:05 UTC
 
 // coverage:ignore-file
 // ignore_for_file: type=lint, unused_import

apps/app_seeds/lib/i18n/strings_en.g.dart

@@ -1167,6 +1167,12 @@ class Translations$profile$en {
 	/// en: 'A short line — what you grow, where'
 	String get aboutHint => 'A short line — what you grow, where';
 
+	/// en: 'Ğ1 address (optional)'
+	String get g1 => 'Ğ1 address (optional)';
+
+	/// en: 'So people can pay you in Ğ1 — separate from your key'
+	String get g1Hint => 'So people can pay you in Ğ1 — separate from your key';
+
 	/// en: 'Your identity'
 	String get yourId => 'Your identity';
 
@@ -1223,6 +1229,12 @@ class Translations$chat$en {
 
 	/// en: 'Set up sharing to send messages'
 	String get offline => 'Set up sharing to send messages';
+
+	/// en: 'Pay in Ğ1'
+	String get payG1 => 'Pay in Ğ1';
+
+	/// en: 'Ğ1 address copied — paste it in your wallet'
+	String get g1Copied => 'Ğ1 address copied — paste it in your wallet';
 }
 
 // Path: trust
@@ -2033,6 +2045,8 @@ extension on Translations {
 			'profile.nameHint' => 'How others see you',
 			'profile.about' => 'About',
 			'profile.aboutHint' => 'A short line — what you grow, where',
+			'profile.g1' => 'Ğ1 address (optional)',
+			'profile.g1Hint' => 'So people can pay you in Ğ1 — separate from your key',
 			'profile.yourId' => 'Your identity',
 			'profile.idHelp' => 'Share this so people can recognise you',
 			'profile.copy' => 'Copy',
@@ -2046,6 +2060,8 @@ extension on Translations {
 			'chat.send' => 'Send',
 			'chat.empty' => 'No messages yet — say hello',
 			'chat.offline' => 'Set up sharing to send messages',
+			'chat.payG1' => 'Pay in Ğ1',
+			'chat.g1Copied' => 'Ğ1 address copied — paste it in your wallet',
 			'trust.none' => 'No one vouches for them yet',
 			'trust.count' => ({required Object n}) => 'Vouched for by ${n}',
 			'trust.vouch' => 'I know this person',

apps/app_seeds/lib/i18n/strings_es.g.dart

@@ -648,6 +648,8 @@ class _Translations$profile$es extends Translations$profile$en {
 	@override String get nameHint => 'Cómo te ven los demás';
 	@override String get about => 'Sobre ti';
 	@override String get aboutHint => 'Una línea — qué cultivas, dónde';
+	@override String get g1 => 'Dirección Ğ1 (opcional)';
+	@override String get g1Hint => 'Para que te paguen en Ğ1 — aparte de tu clave';
 	@override String get yourId => 'Tu identidad';
 	@override String get idHelp => 'Compártela para que te reconozcan';
 	@override String get copy => 'Copiar';
@@ -679,6 +681,8 @@ class _Translations$chat$es extends Translations$chat$en {
 	@override String get send => 'Enviar';
 	@override String get empty => 'Aún no hay mensajes — saluda';
 	@override String get offline => 'Configura el compartir para enviar mensajes';
+	@override String get payG1 => 'Pagar en Ğ1';
+	@override String get g1Copied => 'Dirección Ğ1 copiada — pégala en tu cartera';
 }
 
 // Path: trust
@@ -1363,6 +1367,8 @@ extension on TranslationsEs {
 			'profile.nameHint' => 'Cómo te ven los demás',
 			'profile.about' => 'Sobre ti',
 			'profile.aboutHint' => 'Una línea — qué cultivas, dónde',
+			'profile.g1' => 'Dirección Ğ1 (opcional)',
+			'profile.g1Hint' => 'Para que te paguen en Ğ1 — aparte de tu clave',
 			'profile.yourId' => 'Tu identidad',
 			'profile.idHelp' => 'Compártela para que te reconozcan',
 			'profile.copy' => 'Copiar',
@@ -1376,6 +1382,8 @@ extension on TranslationsEs {
 			'chat.send' => 'Enviar',
 			'chat.empty' => 'Aún no hay mensajes — saluda',
 			'chat.offline' => 'Configura el compartir para enviar mensajes',
+			'chat.payG1' => 'Pagar en Ğ1',
+			'chat.g1Copied' => 'Dirección Ğ1 copiada — pégala en tu cartera',
 			'trust.none' => 'Nadie los avala aún',
 			'trust.count' => ({required Object n}) => 'Avalada por ${n}',
 			'trust.vouch' => 'Conozco a esta persona',

apps/app_seeds/lib/i18n/strings_pt.g.dart

@@ -644,6 +644,8 @@ class _Translations$profile$pt extends Translations$profile$en {
 	@override String get nameHint => 'Como os outros te veem';
 	@override String get about => 'Sobre ti';
 	@override String get aboutHint => 'Uma linha — o que cultivas, onde';
+	@override String get g1 => 'Endereço Ğ1 (opcional)';
+	@override String get g1Hint => 'Para que te paguem em Ğ1 — separado da tua chave';
 	@override String get yourId => 'A tua identidade';
 	@override String get idHelp => 'Partilha-a para que te reconheçam';
 	@override String get copy => 'Copiar';
@@ -675,6 +677,8 @@ class _Translations$chat$pt extends Translations$chat$en {
 	@override String get send => 'Enviar';
 	@override String get empty => 'Ainda não há mensagens — diz olá';
 	@override String get offline => 'Configura a partilha para enviar mensagens';
+	@override String get payG1 => 'Pagar em Ğ1';
+	@override String get g1Copied => 'Endereço Ğ1 copiado — cola-o na tua carteira';
 }
 
 // Path: trust
@@ -1355,6 +1359,8 @@ extension on TranslationsPt {
 			'profile.nameHint' => 'Como os outros te veem',
 			'profile.about' => 'Sobre ti',
 			'profile.aboutHint' => 'Uma linha — o que cultivas, onde',
+			'profile.g1' => 'Endereço Ğ1 (opcional)',
+			'profile.g1Hint' => 'Para que te paguem em Ğ1 — separado da tua chave',
 			'profile.yourId' => 'A tua identidade',
 			'profile.idHelp' => 'Partilha-a para que te reconheçam',
 			'profile.copy' => 'Copiar',
@@ -1368,6 +1374,8 @@ extension on TranslationsPt {
 			'chat.send' => 'Enviar',
 			'chat.empty' => 'Ainda não há mensagens — diz olá',
 			'chat.offline' => 'Configura a partilha para enviar mensagens',
+			'chat.payG1' => 'Pagar em Ğ1',
+			'chat.g1Copied' => 'Endereço Ğ1 copiado — cola-o na tua carteira',
 			'trust.none' => 'Ainda ninguém os avaliza',
 			'trust.count' => ({required Object n}) => 'Avalizada por ${n}',
 			'trust.vouch' => 'Conheço esta pessoa',

apps/app_seeds/lib/services/profile_store.dart

@@ -9,12 +9,21 @@ class ProfileStore {
   final SecretStore _store;
   static const _nameKey = 'tane.social.profile.name';
   static const _aboutKey = 'tane.social.profile.about';
+  static const _g1Key = 'tane.social.profile.g1';
 
   Future<String> name() async => (await _store.read(_nameKey)) ?? '';
   Future<String> about() async => (await _store.read(_aboutKey)) ?? '';
 
-  Future<void> save({required String name, required String about}) async {
+  /// Your Ğ1 (Duniter) address, if you chose to share one.
+  Future<String> g1() async => (await _store.read(_g1Key)) ?? '';
+
+  Future<void> save({
+    required String name,
+    required String about,
+    String g1 = '',
+  }) async {
     await _store.write(_nameKey, name.trim());
     await _store.write(_aboutKey, about.trim());
+    await _store.write(_g1Key, g1.trim());
   }
 }

apps/app_seeds/lib/ui/chat_screen.dart

@@ -1,7 +1,9 @@
 import 'dart:async';
 
 import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
 import 'package:flutter_bloc/flutter_bloc.dart';
+import 'package:url_launcher/url_launcher.dart';
 
 import '../i18n/strings.g.dart';
 import '../services/message_store.dart';
@@ -45,6 +47,7 @@ class _ChatScreenState extends State<ChatScreen> {
   TrustCubit? _trust;
   bool _loading = true;
   String? _peerName;
+  String? _peerG1;
   final _input = TextEditingController();
 
   @override
@@ -94,9 +97,15 @@ class _ChatScreenState extends State<ChatScreen> {
       unawaited(() async {
         try {
           final profile = await live.profile.fetch(widget.peerPubkey);
-          if (profile != null && profile.name.isNotEmpty && mounted) {
+          if (profile != null && mounted) {
-            await widget.profileCache!.setName(widget.peerPubkey, profile.name);
+            if (profile.name.isNotEmpty) {
-            setState(() => _peerName = profile.name);
+              await widget.profileCache!
+                  .setName(widget.peerPubkey, profile.name);
+            }
+            setState(() {
+              if (profile.name.isNotEmpty) _peerName = profile.name;
+              if (profile.g1.isNotEmpty) _peerG1 = profile.g1;
+            });
           }
         } catch (_) {
           // best effort
@@ -105,6 +114,30 @@ class _ChatScreenState extends State<ChatScreen> {
     }
   }
 
+  /// Opens the peer's Ğ1 wallet so you can pay them (Ğ1 is separate from the
+  /// Nostr key — this uses the address they published in their profile). Falls
+  /// back to copying the address if no wallet handles the link.
+  ///
+  /// NOTE: confirm the deep-link scheme for the target wallet (Ğ1nkgo / Ğecko /
+  /// Cesium) — this uses the Cesium web wallet as a universal fallback.
+  Future<void> _payG1() async {
+    final g1 = _peerG1;
+    if (g1 == null) return;
+    final messenger = ScaffoldMessenger.of(context);
+    final t = context.t;
+    final uri = Uri.parse('https://demo.cesium.app/#/app/wallet/$g1/');
+    var launched = false;
+    try {
+      launched = await launchUrl(uri, mode: LaunchMode.externalApplication);
+    } catch (_) {
+      launched = false;
+    }
+    if (!launched && mounted) {
+      await Clipboard.setData(ClipboardData(text: g1));
+      messenger.showSnackBar(SnackBar(content: Text(t.chat.g1Copied)));
+    }
+  }
+
   Future<void> _send() async {
     final cubit = _messages;
     if (cubit == null || _input.text.trim().isEmpty) return;
@@ -126,9 +159,19 @@ class _ChatScreenState extends State<ChatScreen> {
   Widget build(BuildContext context) {
     final messages = _messages;
     final trust = _trust;
+    final t = context.t;
     return Scaffold(
       appBar: AppBar(
         title: Text(_peerName ?? shortPubkey(widget.peerPubkey)),
+        actions: [
+          if (_peerG1 != null)
+            IconButton(
+              key: const Key('chat.payG1'),
+              icon: const Icon(Icons.payments_outlined),
+              tooltip: t.chat.payG1,
+              onPressed: _payG1,
+            ),
+        ],
       ),
       body: _loading || messages == null || trust == null
           ? const Center(child: CircularProgressIndicator())

apps/app_seeds/lib/ui/profile_screen.dart

@@ -30,6 +30,7 @@ class ProfileScreen extends StatefulWidget {
 class _ProfileScreenState extends State<ProfileScreen> {
   final _name = TextEditingController();
   final _about = TextEditingController();
+  final _g1 = TextEditingController();
   bool _loading = true;
   bool _saving = false;
 
@@ -42,6 +43,7 @@ class _ProfileScreenState extends State<ProfileScreen> {
   Future<void> _load() async {
     _name.text = await widget.profileStore.name();
     _about.text = await widget.profileStore.about();
+    _g1.text = await widget.profileStore.g1();
     if (mounted) setState(() => _loading = false);
   }
 
@@ -57,7 +59,8 @@ class _ProfileScreenState extends State<ProfileScreen> {
     final messenger = ScaffoldMessenger.of(context);
     final t = context.t;
     setState(() => _saving = true);
-    await widget.profileStore.save(name: _name.text, about: _about.text);
+    await widget.profileStore
+        .save(name: _name.text, about: _about.text, g1: _g1.text);
 
     // Best-effort publish to the network so peers see the name.
     final relays = await widget.settings.relayUrls();
@@ -67,6 +70,7 @@ class _ProfileScreenState extends State<ProfileScreen> {
         await session.profile.publish(
           name: _name.text.trim(),
           about: _about.text.trim(),
+          g1: _g1.text.trim(),
         );
         await session.close();
       } catch (_) {
@@ -82,6 +86,7 @@ class _ProfileScreenState extends State<ProfileScreen> {
   void dispose() {
     _name.dispose();
     _about.dispose();
+    _g1.dispose();
     super.dispose();
   }
 
@@ -116,6 +121,16 @@ class _ProfileScreenState extends State<ProfileScreen> {
                     helperText: t.profile.aboutHint,
                   ),
                 ),
+                const SizedBox(height: 16),
+                TextField(
+                  key: const Key('profile.g1'),
+                  controller: _g1,
+                  decoration: InputDecoration(
+                    labelText: t.profile.g1,
+                    helperText: t.profile.g1Hint,
+                    helperMaxLines: 2,
+                  ),
+                ),
                 const SizedBox(height: 24),
                 FilledButton(
                   key: const Key('profile.save'),

packages/commons_core/lib/src/social/nostr/nostr_profile_transport.dart

@@ -19,11 +19,13 @@ class NostrProfileTransport implements ProfileTransport {
     String name = '',
     String about = '',
     String picture = '',
+    String g1 = '',
   }) async {
     final content = jsonEncode({
       if (name.isNotEmpty) 'name': name,
       if (about.isNotEmpty) 'about': about,
       if (picture.isNotEmpty) 'picture': picture,
+      if (g1.isNotEmpty) 'g1': g1,
     });
     final event = Event.from(
       kind: kindMetadata,
@@ -50,6 +52,7 @@ class NostrProfileTransport implements ProfileTransport {
         name: (map['name'] as String?) ?? '',
         about: (map['about'] as String?) ?? '',
         picture: (map['picture'] as String?) ?? '',
+        g1: (map['g1'] as String?) ?? '',
       );
     } catch (_) {
       return UserProfile(pubkeyHex: pubkeyHex);

packages/commons_core/lib/src/social/profile_transport.dart

@@ -6,6 +6,7 @@ class UserProfile {
     this.name = '',
     this.about = '',
     this.picture = '',
+    this.g1 = '',
   });
 
   final String pubkeyHex;
@@ -13,7 +14,12 @@ class UserProfile {
   final String about;
   final String picture;
 
-  bool get isEmpty => name.isEmpty && about.isEmpty && picture.isEmpty;
+  /// Optional Ğ1 (Duniter) address the person chose to publish, so peers can pay
+  /// them in Ğ1. Separate from the Nostr key; empty when not shared.
+  final String g1;
+
+  bool get isEmpty =>
+      name.isEmpty && about.isEmpty && picture.isEmpty && g1.isEmpty;
 }
 
 /// Publish/fetch public profile metadata. Kind:0 is replaceable — publishing
@@ -21,7 +27,7 @@ class UserProfile {
 /// sibling of the offer/message/trust transports over the same connection.
 abstract interface class ProfileTransport {
   /// Publishes (replaces) this identity's profile.
-  Future<void> publish({String name, String about, String picture});
+  Future<void> publish({String name, String about, String picture, String g1});
 
   /// Fetches [pubkeyHex]'s latest profile, or null if they never published one.
   Future<UserProfile?> fetch(String pubkeyHex);

packages/commons_core/test/social/nostr_profile_test.dart

@@ -16,8 +16,11 @@ void main() {
   test('publish then fetch round-trips a profile (kind:0)', () async {
     final alice = await idFor(1);
     final aliceConn = await NostrConnection.connect(relay.url, identity: alice);
-    await NostrProfileTransport(aliceConn)
+    await NostrProfileTransport(aliceConn).publish(
-        .publish(name: 'Alicia', about: 'Guardo tomate rosa');
+      name: 'Alicia',
+      about: 'Guardo tomate rosa',
+      g1: 'G1abc123',
+    );
 
     // Anyone else can fetch it.
     final bob = await idFor(2);
@@ -28,6 +31,7 @@ void main() {
     expect(fetched, isNotNull);
     expect(fetched!.name, 'Alicia');
     expect(fetched.about, 'Guardo tomate rosa');
+    expect(fetched.g1, 'G1abc123');
 
     await aliceConn.close();
     await bobConn.close();