fix(mailer): fall back to user account for devise email locale (#267)

Devise emails sent from unauthenticated flows (password reset,
unlock, confirmation re-send) were always rendered in the default
locale because Current.account is nil in that context. Use the
user's first account as a fallback so the email respects the
account locale configured by the user.

app/models/user.rb

@@ -132,7 +132,8 @@ class User < ApplicationRecord
   end
 
   def send_devise_notification(notification, *)
-    devise_mailer.with(account: Current.account).send(notification, self, *).deliver_later
+    account = Current.account || accounts.first
+    devise_mailer.with(account: account).send(notification, self, *).deliver_later
   end
 
   def set_password_and_uid

spec/models/user_spec.rb

@@ -283,6 +283,33 @@ RSpec.describe User do
     end
   end
 
+  describe '#send_devise_notification' do
+    let(:account) { create(:account, locale: 'pt_BR') }
+    let(:recipient) { create(:user, account: account) }
+    let(:mailer_double) { double(reset_password_instructions: double(deliver_later: nil)) } # rubocop:disable RSpec/VerifiedDoubles
+
+    before do
+      Current.reset
+      allow(Devise::Mailer).to receive(:with).and_return(mailer_double)
+    end
+
+    it 'falls back to the user account when Current.account is nil' do
+      recipient.send_reset_password_instructions
+
+      expect(Devise::Mailer).to have_received(:with).with(account: account)
+    end
+
+    it 'prefers Current.account when it is set' do
+      other_account = create(:account)
+      create(:account_user, user: recipient, account: other_account)
+      Current.account = other_account
+
+      recipient.send_reset_password_instructions
+
+      expect(Devise::Mailer).to have_received(:with).with(account: other_account)
+    end
+  end
+
   describe 'destroy' do
     it 'nullifies scheduled messages author when user has sent scheduled messages' do
       account = create(:account)