feat(voice): add VoiceRepository and provider registration

lib/data/repositories/voice_repository.dart

@@ -0,0 +1,12 @@
+import 'dart:typed_data';
+
+import '../api/voice_api.dart';
+
+class VoiceRepository {
+  final VoiceApi _api;
+  const VoiceRepository(this._api);
+
+  Future<VoiceStatus> checkStatus() => _api.checkStatus();
+  Future<String> transcribe(Uint8List audioBytes) => _api.transcribe(audioBytes);
+  Future<Uint8List> synthesise(String text) => _api.synthesise(text);
+}

lib/providers/api_client_provider.dart

@@ -7,6 +7,7 @@ import '../data/api/auth_api.dart';
 import '../data/api/briefing_api.dart';
 import '../data/api/chat_api.dart';
 import '../data/api/knowledge_api.dart';
+import '../data/api/voice_api.dart';
 import '../data/api/milestones_api.dart';
 import '../data/api/notes_api.dart';
 import '../data/api/projects_api.dart';
@@ -16,6 +17,7 @@ import '../data/api/tasks_api.dart';
 import '../data/repositories/auth_repository.dart';
 import '../data/repositories/chat_repository.dart';
 import '../data/repositories/knowledge_repository.dart';
+import '../data/repositories/voice_repository.dart';
 import '../data/repositories/milestones_repository.dart';
 import '../data/repositories/notes_repository.dart';
 import '../data/repositories/projects_repository.dart';
@@ -100,3 +102,11 @@ final briefingApiProvider = Provider<BriefingApi>((ref) {
 final settingsApiProvider = Provider<SettingsApi>((ref) {
   return SettingsApi(ref.watch(dioProvider));
 });
+
+final voiceApiProvider = Provider<VoiceApi>((ref) {
+  return VoiceApi(ref.watch(dioProvider));
+});
+
+final voiceRepositoryProvider = Provider<VoiceRepository>((ref) {
+  return VoiceRepository(ref.watch(voiceApiProvider));
+});