feat(dm): wire full emoji picker for custom reactions

The "+" affordance in the DM reaction long-press row returned
ReactionPickerResult(openFullPicker: true) into a no-op caller stub —
tapping it dismissed the sheet and did nothing (#4710).

Wire it to pro_image_editor's built-in EmojiEditor (already a direct
dependency for the video editor) via a new FullReactionEmojiPickerSheet,
shown as a Divine dark-styled bottom sheet. The picked emoji flows
through the existing ConversationReactionToggled path unchanged — no new
dependency and no repository/protocol work, since the NIP-17
wrapped-reaction plumbing already accepts arbitrary emoji.

This supersedes the earlier "temporarily remove the + button" approach
per review on #4711, and clears the dead openFullPicker seam and the
stale TODO(#4633) breadcrumbs by making the path live.

Closes #4710

Author: realmeylisdev

mobile/lib/screens/inbox/conversation/conversation_view.dart

@@ -378,21 +378,13 @@ class _MessageList extends StatelessWidget {
     if (!context.mounted) return;
 
     if (result.emoji != null) {
-      context.read<ConversationReactionsCubit>().add(
-        ConversationReactionToggled(
-          conversationId: message.conversationId,
-          messageId: message.id,
-          messageAuthorPubkey: message.senderPubkey,
-          emoji: result.emoji!,
-        ),
-      );
+      _toggleReaction(context, message, result.emoji!);
       return;
     }
     if (result.openFullPicker) {
-      // Full picker integration is staged for v1 by triggering the
-      // emoji_picker_flutter sheet. Caller-side gating keeps this
-      // off the critical path while the dependency is wired in.
-      // TODO(#4633): wire full emoji_picker_flutter sheet.
+      final emoji = await FullReactionEmojiPickerSheet.show(context: context);
+      if (emoji == null || !context.mounted) return;
+      _toggleReaction(context, message, emoji);
       return;
     }
     final action = result.action;
@@ -417,6 +409,17 @@ class _MessageList extends StatelessWidget {
     }
   }
 
+  void _toggleReaction(BuildContext context, DmMessage message, String emoji) {
+    context.read<ConversationReactionsCubit>().add(
+      ConversationReactionToggled(
+        conversationId: message.conversationId,
+        messageId: message.id,
+        messageAuthorPubkey: message.senderPubkey,
+        emoji: emoji,
+      ),
+    );
+  }
+
   @override
   Widget build(BuildContext context) {
     return ListView.builder(

mobile/lib/screens/inbox/conversation/widgets/full_reaction_emoji_picker_sheet.dart

@@ -0,0 +1,56 @@
+// ABOUTME: Full emoji picker bottom sheet for DM custom reactions. Wraps
+// ABOUTME: pro_image_editor's EmojiEditor in a Divine dark-styled sheet.
+
+import 'package:divine_ui/divine_ui.dart';
+import 'package:flutter/material.dart';
+import 'package:pro_image_editor/pro_image_editor.dart';
+
+/// Bottom sheet that lets the user pick any emoji as a DM reaction.
+///
+/// Wraps [EmojiEditor] from `pro_image_editor` — already a direct
+/// dependency for the video editor — so the full emoji set is available
+/// beyond the six quick reactions, without adding a new picker package.
+/// The picked emoji flows through the same [ConversationReactionToggled]
+/// path as a quick reaction.
+class FullReactionEmojiPickerSheet {
+  /// Visible height of the picker body, excluding the keyboard inset.
+  static const double _bodyHeight = 320;
+
+  /// Dark-mode editor configuration. Matches the picker grid background to
+  /// the surrounding sheet so the surface reads as a single dark panel.
+  static const _editorConfigs = ProImageEditorConfigs(
+    emojiEditor: EmojiEditorConfigs(
+      style: EmojiEditorStyle(
+        backgroundColor: VineTheme.surfaceBackground,
+      ),
+    ),
+  );
+
+  /// Shows the picker and resolves to the selected emoji, or `null` if the
+  /// sheet was dismissed without a choice.
+  static Future<String?> show({required BuildContext context}) async {
+    final layer = await showModalBottomSheet<EmojiLayer>(
+      context: context,
+      backgroundColor: VineTheme.surfaceBackground,
+      isScrollControlled: true,
+      shape: const RoundedRectangleBorder(
+        borderRadius: BorderRadius.vertical(
+          top: Radius.circular(VineTheme.bottomSheetBorderRadius),
+        ),
+      ),
+      builder: (sheetContext) {
+        return SafeArea(
+          top: false,
+          child: ConstrainedBox(
+            constraints: BoxConstraints(
+              maxHeight:
+                  _bodyHeight + MediaQuery.viewInsetsOf(sheetContext).bottom,
+            ),
+            child: const EmojiEditor(configs: _editorConfigs),
+          ),
+        );
+      },
+    );
+    return layer?.emoji;
+  }
+}

mobile/lib/screens/inbox/conversation/widgets/widgets.dart

@@ -1,6 +1,7 @@
 export 'collaborator_invite_card.dart';
 export 'conversation_app_bar.dart';
 export 'empty_conversation.dart';
+export 'full_reaction_emoji_picker_sheet.dart';
 export 'message_actions_sheet.dart';
 export 'message_bubble.dart';
 export 'message_input_bar.dart';

mobile/test/screens/inbox/conversation/conversation_view_test.dart

@@ -21,6 +21,7 @@ import 'package:openvine/providers/user_profile_providers.dart';
 import 'package:openvine/screens/inbox/conversation/conversation_view.dart';
 import 'package:openvine/screens/inbox/conversation/widgets/widgets.dart';
 import 'package:openvine/services/video_event_service.dart';
+import 'package:pro_image_editor/pro_image_editor.dart';
 import 'package:visibility_detector/visibility_detector.dart';
 
 import '../../../builders/video_event_builder.dart';
@@ -1208,6 +1209,26 @@ void main() {
           );
         },
       );
+
+      // Closes #4710: the "+" affordance was a no-op stub. Proves the
+      // long-press → "+" path now dismisses the reaction overlay and
+      // opens the full emoji picker.
+      testWidgets(
+        'tapping "+" in the reaction row opens the full emoji picker',
+        (tester) async {
+          await pumpWithMessage(tester);
+
+          await tester.longPress(find.text('Hello there!'));
+          await tester.pumpAndSettle();
+
+          await tester.tap(
+            find.bySemanticsLabel(l10n.dmReactionAddCustomA11yLabel),
+          );
+          await tester.pumpAndSettle();
+
+          expect(find.byType(EmojiEditor), findsOneWidget);
+        },
+      );
     });
   });
 }

mobile/test/screens/inbox/conversation/widgets/full_reaction_emoji_picker_sheet_test.dart

@@ -0,0 +1,77 @@
+// ABOUTME: Widget tests for FullReactionEmojiPickerSheet.
+// ABOUTME: Verifies the sheet mounts the emoji picker and resolves its result.
+
+import 'dart:async';
+
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:openvine/screens/inbox/conversation/widgets/full_reaction_emoji_picker_sheet.dart';
+import 'package:pro_image_editor/pro_image_editor.dart';
+
+import '../../../../helpers/test_provider_overrides.dart';
+
+void main() {
+  group('FullReactionEmojiPickerSheet', () {
+    testWidgets('mounts the emoji picker when shown', (tester) async {
+      await tester.pumpWidget(
+        testMaterialApp(
+          home: Builder(
+            builder: (context) {
+              return Scaffold(
+                body: TextButton(
+                  onPressed: () {
+                    unawaited(
+                      FullReactionEmojiPickerSheet.show(context: context),
+                    );
+                  },
+                  child: const Text('open'),
+                ),
+              );
+            },
+          ),
+        ),
+      );
+
+      await tester.tap(find.text('open'));
+      await tester.pumpAndSettle();
+
+      expect(find.byType(EmojiEditor), findsOneWidget);
+    });
+
+    testWidgets('resolves to null when dismissed without a choice', (
+      tester,
+    ) async {
+      String? selected;
+      var completed = false;
+      await tester.pumpWidget(
+        testMaterialApp(
+          home: Builder(
+            builder: (context) {
+              return Scaffold(
+                body: TextButton(
+                  onPressed: () async {
+                    selected = await FullReactionEmojiPickerSheet.show(
+                      context: context,
+                    );
+                    completed = true;
+                  },
+                  child: const Text('open'),
+                ),
+              );
+            },
+          ),
+        ),
+      );
+
+      await tester.tap(find.text('open'));
+      await tester.pumpAndSettle();
+
+      // Dismiss the sheet without selecting an emoji.
+      Navigator.of(tester.element(find.byType(EmojiEditor))).pop();
+      await tester.pumpAndSettle();
+
+      expect(completed, isTrue);
+      expect(selected, isNull);
+    });
+  });
+}

mobile/test/screens/inbox/conversation/widgets/reaction_picker_overlay_test.dart

@@ -69,15 +69,37 @@ void main() {
       expect(find.text('Copy text'), findsNothing);
     });
 
-    testWidgets('dismisses after selecting the full-picker affordance', (
+    testWidgets('"+" affordance dismisses and pops openFullPicker', (
       tester,
     ) async {
-      await openOverlay(tester);
+      ReactionPickerResult? result;
+      await tester.pumpWidget(
+        testMaterialApp(
+          home: Builder(
+            builder: (context) {
+              return Scaffold(
+                body: TextButton(
+                  onPressed: () async {
+                    result = await ReactionPickerOverlay.show(
+                      context: context,
+                      isSent: false,
+                    );
+                  },
+                  child: const Text('open'),
+                ),
+              );
+            },
+          ),
+        ),
+      );
+      await tester.tap(find.text('open'));
+      await tester.pumpAndSettle();
 
       await tester.tap(find.bySemanticsLabel('Add custom emoji reaction'));
       await tester.pumpAndSettle();
 
       expect(find.bySemanticsLabel('Add custom emoji reaction'), findsNothing);
+      expect(result?.openFullPicker, isTrue);
     });
 
     testWidgets('omits picker row when showPicker is false', (tester) async {