fix: resolve test compilation errors and restore upstream VERSION

- Add missing interface methods to test stubs (RemoveGroupFromUserAllowedGroups,
  GetNotifyCodeUserRate, IncrNotifyCodeUserRate, UpdateGroupIDByUserAndGroup)
- Fix NewUserService call signatures (add 4th param)
- Fix GetAccountCount return signature (3 values)
- Update api_contract_test.go snapshots for balance_notify fields
- Restore resolveOpenAIMessagesDispatchMappedModel function
- Reset VERSION to upstream 0.1.112

backend/internal/service/admin_service_apikey_test.go

@@ -70,6 +70,9 @@ func (s *userRepoStubForGroupUpdate) UpdateTotpSecret(context.Context, int64, *s
 }
 func (s *userRepoStubForGroupUpdate) EnableTotp(context.Context, int64) error  { panic("unexpected") }
 func (s *userRepoStubForGroupUpdate) DisableTotp(context.Context, int64) error { panic("unexpected") }
+func (s *userRepoStubForGroupUpdate) RemoveGroupFromUserAllowedGroups(context.Context, int64, int64) error {
+	panic("unexpected")
+}
 
 // apiKeyRepoStubForGroupUpdate implements APIKeyRepository for AdminUpdateAPIKeyGroupID tests.
 type apiKeyRepoStubForGroupUpdate struct {
@@ -152,6 +155,9 @@ func (s *apiKeyRepoStubForGroupUpdate) ResetRateLimitWindows(context.Context, in
 func (s *apiKeyRepoStubForGroupUpdate) GetRateLimitData(context.Context, int64) (*APIKeyRateLimitData, error) {
 	panic("unexpected")
 }
+func (s *apiKeyRepoStubForGroupUpdate) UpdateGroupIDByUserAndGroup(context.Context, int64, int64, int64) (int64, error) {
+	panic("unexpected")
+}
 
 // groupRepoStubForGroupUpdate implements GroupRepository for AdminUpdateAPIKeyGroupID tests.
 type groupRepoStubForGroupUpdate struct {
@@ -194,7 +200,7 @@ func (s *groupRepoStubForGroupUpdate) ListActiveByPlatform(context.Context, stri
 func (s *groupRepoStubForGroupUpdate) ExistsByName(context.Context, string) (bool, error) {
 	panic("unexpected")
 }
-func (s *groupRepoStubForGroupUpdate) GetAccountCount(context.Context, int64) (int64, error) {
+func (s *groupRepoStubForGroupUpdate) GetAccountCount(context.Context, int64) (int64, int64, error) {
 	panic("unexpected")
 }
 func (s *groupRepoStubForGroupUpdate) DeleteAccountGroupsByGroupID(context.Context, int64) (int64, error) {

backend/internal/service/auth_service_register_test.go

@@ -119,6 +119,14 @@ func (s *emailCacheStub) SetPasswordResetEmailCooldown(ctx context.Context, emai
 	return nil
 }
 
+func (s *emailCacheStub) GetNotifyCodeUserRate(ctx context.Context, userID int64) (int64, error) {
+	return 0, nil
+}
+
+func (s *emailCacheStub) IncrNotifyCodeUserRate(ctx context.Context, userID int64, window time.Duration) (int64, error) {
+	return 0, nil
+}
+
 func newAuthService(repo *userRepoStub, settings map[string]string, emailCache EmailCache) *AuthService {
 	cfg := &config.Config{
 		JWT: config.JWTConfig{

backend/internal/service/user_service_test.go

@@ -49,6 +49,9 @@ func (m *mockUserRepo) AddGroupToAllowedGroups(context.Context, int64, int64) er
 func (m *mockUserRepo) UpdateTotpSecret(context.Context, int64, *string) error      { return nil }
 func (m *mockUserRepo) EnableTotp(context.Context, int64) error                     { return nil }
 func (m *mockUserRepo) DisableTotp(context.Context, int64) error                    { return nil }
+func (m *mockUserRepo) RemoveGroupFromUserAllowedGroups(context.Context, int64, int64) error {
+	return nil
+}
 
 // --- mock: APIKeyAuthCacheInvalidator ---