feat: import Chinese-localized Buzz source snapshot

Signed-off-by: cls_宁波本机 <908705107@qq.com>

mobile/lib/shared/emoji/emoji_data_provider.dart

@@ -0,0 +1,38 @@
+import 'dart:convert';
+
+import 'package:flutter/foundation.dart';
+import 'package:flutter/services.dart' show rootBundle;
+import 'package:hooks_riverpod/hooks_riverpod.dart';
+
+import 'emoji_data.dart';
+
+/// Asset path for the generated dataset. See `mobile/scripts/generate-emoji-data.mjs`.
+const emojiDataAssetPath = 'assets/emoji/emoji-data.json';
+
+/// Decode + parse off the UI isolate. ~1.9k entries is fast but not free, and
+/// the picker sheet animates in while this runs.
+EmojiDataset _parseEmojiData(String source) {
+  return EmojiDataset.fromJson(jsonDecode(source) as Map<String, dynamic>);
+}
+
+/// The standard emoji dataset, loaded once from the app bundle.
+final emojiDatasetProvider = FutureProvider<EmojiDataset>((ref) async {
+  final source = await rootBundle.loadString(emojiDataAssetPath);
+  return compute(_parseEmojiData, source);
+});
+
+/// Synchronous read of the dataset — [EmojiDataset.empty] while loading or on
+/// error. Convenience for widgets that only need the resolved value, mirroring
+/// `customEmojiListProvider`.
+final emojiDatasetOrEmptyProvider = Provider<EmojiDataset>((ref) {
+  return ref.watch(emojiDatasetProvider).value ?? EmojiDataset.empty;
+});
+
+/// Every glyph in the dataset, as a set for membership tests.
+///
+/// Built once per dataset load rather than per message: `isEmojiOnlyMessage`
+/// runs on every rendered body, and materializing ~1.9k keys there would be a
+/// per-frame cost.
+final nativeEmojiGlyphsProvider = Provider<Set<String>>((ref) {
+  return ref.watch(emojiDatasetOrEmptyProvider).nativeToShortcode.keys.toSet();
+});