feat: Add article messages along with bot responses (#7993)

ref: https://linear.app/chatwoot/issue/CW-2464/bot-should-also-return-links-to-the-information

enterprise/app/services/openai/embeddings_service.rb

@@ -8,7 +8,7 @@ class Openai::EmbeddingsService
   def fetch_embeddings(input)
     url = 'https://api.openai.com/v1/embeddings'
     headers = {
-      'Authorization' => "Bearer #{ENV.fetch('OPENAI_API_KEY')}",
+      'Authorization' => "Bearer #{ENV.fetch('OPENAI_API_KEY', '')}",
       'Content-Type' => 'application/json'
     }
     data = {
@@ -17,6 +17,6 @@ class Openai::EmbeddingsService
     }
 
     response = Net::HTTP.post(URI(url), data.to_json, headers)
-    JSON.parse(response.body)['data'].pick('embedding')
+    JSON.parse(response.body)['data']&.pick('embedding')
   end
 end