Restructure omni services and add Chatwoot research snapshot

research/chatwoot/app/controllers/google/callbacks_controller.rb

@@ -0,0 +1,27 @@
+class Google::CallbacksController < OauthCallbackController
+  include GoogleConcern
+
+  def find_channel_by_email
+    # find by imap_login first, and then by email
+    # this ensures the legacy users can migrate correctly even if inbox email address doesn't match
+    imap_channel = Channel::Email.find_by(imap_login: users_data['email'], account: account)
+    return imap_channel if imap_channel
+
+    Channel::Email.find_by(email: users_data['email'], account: account)
+  end
+
+  private
+
+  def provider_name
+    'google'
+  end
+
+  def imap_address
+    'imap.gmail.com'
+  end
+
+  def oauth_client
+    # from GoogleConcern
+    google_client
+  end
+end